Funds For Institutions Series N-CSRS Certified semi-annual shareholder report (management investment company)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number: 811-05149 and 811-10631

Name of Fund: Funds For Institutions Series

BlackRock Premier Government Institutional Fund

BlackRock Select Treasury Strategies Institutional Fund

BlackRock Treasury Strategies Institutional Fund

FFI Government Fund

FFI Treasury

Master Institutional Money Market LLC

Master Premier Government Institutional Portfolio

Master Treasury Strategies Institutional Portfolio

Fund Address:    100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: John M. Perlowski, Chief Executive Officer, Funds For Institutions Series and Master Institutional Money Market LLC, 55 East 52^nd Street, New York, NY 10055

Registrants’ telephone number, including area code: (800) 626-1960

Date of fiscal year end: 04/30/2019

Date of reporting period: 10/31/2018

Item 1 – Report to Stockholders

OCTOBER 31, 2018

SEMI-ANNUAL REPORT (UNAUDITED)

Funds For Institutions Series

^Ø  BlackRock Premier Government Institutional Fund

^Ø  BlackRock Treasury Strategies Institutional Fund

^Ø  BlackRock Select Treasury Strategies Institutional Fund

^Ø  FFI Government Fund

^Ø  FFI Treasury Fund

Not FDIC Insured • May Lose Value • No Bank Guarantee

The Markets in Review

Dear Shareholder,

In the 12 months ended October 31, 2018, ongoing strength in corporate profits drove the equity market higher, while rising interest rates constrained bond returns. Though the market’s appetite for risk remained healthy, risk-taking was tempered somewhat, as shorter-term, higher-quality securities led the bond market, and U.S. equities outperformed most international stock markets.

In international markets, the rising value of the U.S. dollar limited U.S. investors’ returns for the reporting period. When the U.S. dollar appreciates relative to foreign currencies, the value of international investments declines in U.S. dollar terms. Volatility rose in emerging market stocks, which are relatively sensitive to changes in the U.S. dollar. U.S.-China trade relations and debt concerns adversely affected the Chinese stock market, while Turkey and Argentina became embroiled in currency crises, largely due to hyperinflation in both countries. An economic slowdown in Europe led to negative performance for European equities.

In fixed income markets, short-term U.S. Treasury interest rates rose the fastest, while longer-term rates slightly increased. This led to a negative return for long-term U.S. Treasuries and a substantial flattening of the yield curve. Many investors are concerned with the flattening yield curve as a harbinger of recession. However, given the extraordinary monetary measures in the last decade, we believe a more accurate barometer for the economy is the returns along the risk spectrums in stock and bond markets. Although the fundamentals in credit markets remained relatively solid, investment-grade bonds declined slightly, and high-yield bonds posted modest returns.

In response to rising growth and inflation, the U.S. Federal Reserve (the “Fed”) increased short-term interest rates four times during the reporting period. The Fed also continued to reduce its balance sheet during the reporting period, gradually reversing the unprecedented stimulus measures it enacted after the financial crisis. We believe the Fed is likely to continue to raise interest rates in the coming year. By our estimation, the Fed’s neutral interest rate, or the theoretical rate that is neither stimulative nor restrictive to the economy, is approximately 3.0%. With that perspective, the Fed’s current policy is still mildly stimulative to the U.S. economy, which leaves room for further Fed rate hikes to arrive at monetary policy that is a neutral factor for economic growth.

The U.S. economy continued to gain momentum despite the Fed’s modest reduction of economic stimulus; unemployment declined to 3.7%, the lowest rate of unemployment in almost 50 years. The number of job openings reached a record high of more than 7 million, which exceeded the total number of unemployed workers. Strong economic performance has justified the Fed’s somewhat faster pace of rate hikes, as several inflation measures and investors’ expectations for inflation have already surpassed the Fed’s target of 2.0% per year.

While markets have recently focused on the risk of rising long-term interest rates, we continue to believe the primary risk to economic expansion is trade protectionism that could lead to slower global trade and unintended consequences for the globalized supply chain. So far, U.S. tariffs have only had a modest negative impact on economic growth, but the fear of an escalating trade war has stifled market optimism somewhat, leading to higher volatility in risk assets. The outcome of trade negotiations between the United States and China is likely to influence the global growth trajectory and set the tone for free trade in many other nations. Easing of tensions could lead to greater upside for markets, while additional tariffs could adversely affect investor sentiment.

In this environment, investors need to think globally, extend their scope across a broad array of asset classes, and be nimble as market conditions change. We encourage you to talk with your financial advisor and visit blackrock.com for further insight about investing in today’s markets.

Sincerely,

Rob Kapito

President, BlackRock Advisors, LLC

Rob Kapito

President, BlackRock Advisors, LLC

Total Returns as of October 31, 2018
	6-month	12-month
U.S. large cap equities (S&P 500® Index)	3.40%	7.35%
U.S. small cap equities (Russell 2000® Index)	(1.37)	1.85
International equities (MSCI Europe, Australasia, Far East Index)	(9.92)	(6.85)
Emerging market equities (MSCI Emerging Markets Index)	(16.53)	(12.52)
3-month Treasury bills (ICE BofAML 3-Month U.S. Treasury Bill Index)	0.99	1.68
U.S. Treasury securities (ICE BofAML 10-Year U.S. Treasury Index)	(0.60)	(4.37)
U.S. investment grade bonds (Bloomberg Barclays U.S. Aggregate Bond Index)	(0.19)	(2.05)
Tax-exempt municipal bonds (S&P Municipal Bond Index)	0.45	(0.31)
U.S. high yield bonds (Bloomberg Barclays U.S. Corporate High Yield 2% Issuer Capped Index)	1.14	0.98
Past performance is no guarantee of future results. Index performance is shown for illustrative purposes only. You cannot invest directly in an index.

2 THIS PAGEISNOT PARTOF YOUR FUND REPORT

Table of Contents

	Page
The Markets in Review		2
Semi-Annual Report:
Money Market Overview		4
Fund Information		5
Disclosure of Expenses		6
Fund Financial Statements:
Schedules of Investments		7
Statements of Assets and Liabilities		10
Statements of Operations		11
Statements of Changes in Net Assets		12
Fund Financial Highlights		15
Fund Notes to Financial Statements		20
Master Portfolio Information		24
Master Portfolio Financial Statements:
Schedules of Investments		25
Statements of Assets and Liabilities		28
Statements of Operations		29
Statements of Changes in Net Assets		30
Master Portfolio Financial Highlights		31
Master Portfolio Notes to Financial Statements		33
Disclosure of Investment Advisory Agreements		36
Director and Officer Information		40
Additional Information		41

3

Money Market Overview  For the Six-Month Period Ended October 31, 2018

Noteworthy market conditions for the six-month period ended October 31, 2018 included the continued steady removal of monetary accommodation by the Federal Open Market Committee (“FOMC”), the ongoing gradual reduction of the Fed’s balance sheet, increased Treasury issuance and various geopolitical events including trade.

Heading into the end of the third quarter of 2018, at their September 26, 2018 FOMC meeting, the FOMC raised interest rates by 0.25% for the third time this year bringing the Fed funds target rate range to 2.00% -- 2.25%. In the statement issued in conjunction with the September meeting, the FOMC remained upbeat about economic growth, employment and inflation, while signaling that gradual hikes in interest rates remain appropriate.

Following the resolution of the debt ceiling limit in early February, the U.S. Treasury increased net bill supply by an estimated $330 billion over a six-week period ending March 29, 2018. The massive amount of supply, in combination with the base erosion and antiabuse tax stemming from the repatriation of U.S. dollars held offshore, pressured short term credit spreads wider during the first half of the year. These pressures generally led money market fund managers to maintain a conservative posture leading up to the June and September 2018 FOMC meetings and in advance of seasonal redemptions that occur at quarter end. Credit spreads, as reflected in the differential between three-month London Inter-Bank Offered Rate (“LIBOR”) and overnight index swaps (“OIS”), widened significantly as the market adjusted to the surge in front-end supply. The trend continued up until the better-than-expected tax-receipts in April when a contraction and stabilization of the credit spreads occurred. This was evidenced by the three-month LIBOR and OIS spread contracting to 40 basis points in June and to 20 basis points in September, down from a high of 60 basis points earlier in the year.

Despite an increase in stock market volatility in October and a tightening of financial conditions, Fed officials are generally centered on the soundness of economic conditions. An additional 0.25% rate increase by the FOMC is anticipated in December. While international trade dynamics could eventually become a headwind to economic growth, further rate hikes on a quarterly basis are possible in our view over much of 2019. However, a more significant tightening of financial conditions would represent a threat to this outlook. By our estimation, credit spreads should remain near recent levels in the weeks ahead. That said, we believe that increased Treasury bill issuance, an ongoing contraction in liquidity in the banking system from the normalization of the Fed’s balance sheet, and year-end balance sheet pressures at certain global systemically important banks could contribute to modest credit spread widening later in the year.

Past performance is no guarantee of future results. Index performance is shown for illustrative purposes only. You cannot invest directly in an index.

4 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Fund Information  as of October 31, 2018 Funds For Institutions Series

BlackRock Premier Government Institutional Fund

BlackRock Premier Government Institutional Fund’s (the “Fund”) investment objective is to seek current income as is consistent with liquidity and stability of principal.

On May 24, 2017, the Board of Directors on behalf of the Fund approved a proposal to close the Fund to share purchases. Accordingly, effective December 1, 2017, the Fund no longer accepts purchase orders.

	7-Day SEC Yield			7-Day Yield
As of October 31, 2018		1.97	%		1.97	%

BlackRock Treasury Strategies Institutional Fund

BlackRock Treasury Strategies Institutional Fund’s (the “Fund”) investment objective is to seek current income as is consistent with liquidity and stability of principal.

On May 24, 2017, the Board of Directors on behalf of the Fund approved a proposal to close the Fund to share purchases. Accordingly, effective December 1, 2017, the Fund no longer accepts purchase orders.

	7-Day SEC Yield			7-Day Yield
As of October 31, 2018		1.81	%		1.81	%

BlackRock Select Treasury Strategies Institutional Fund

BlackRock Select Treasury Strategies Institutional Fund’s (the “Fund”) investment objective is to seek current income as is consistent with liquidity and stability of principal.

On May 24, 2017, the Board of Directors on behalf of the Fund approved a proposal to close the Fund to share purchases. Accordingly, effective December 1, 2017, the Fund no longer accepts purchase orders.

	7-Day SEC Yield			7-Day Yield
As of October 31, 2018		1.97	%		1.97	%

FFI Government Fund

FFI Government Fund’s (the “Fund”) investment objective is to seek current income as is consistent with liquidity and stability of principal.

On February 18, 2016, the Board of Directors on behalf of the Fund approved a proposal to close the Fund to share purchases. Accordingly, effective September 1, 2016, the Fund no longer accepts purchase orders.

	7-Day SEC Yield			7-Day Yield
As of October 31, 2018		1.68	%		1.68	%

Portfolio Composition	Percent of Net Assets
Repurchase Agreements		83	%
U.S. Treasury Obligations		14
U.S. Government Sponsored Agency Obligations		1
Other Assets Less Liabilities		2

FFI Treasury Fund

FFI Treasury Fund’s (the “Fund”) investment objective is to seek current income as is consistent with liquidity and stability of principal.

On February 18, 2016, the Board of Directors on behalf of the Fund approved a proposal to close the Fund to share purchases. Accordingly, effective September 1, 2016, the Fund no longer accepts purchase orders.

	7-Day SEC Yield			7-Day Yield
As of October 31, 2018		1.80	%		1.80	%

The 7-Day SEC Yields may differ from the 7-Day Yields shown above due to the fact that the 7-Day SEC Yields exclude distributed capital gains.

Past performance is not indicative of future results.

Portfolio Composition	Percent of Net Assets
U.S. Treasury Obligations		100	%

FUND INFORMATION 5

Disclosure of Expenses Funds For Institutions Series

Shareholders of these Funds may incur the following charges: (a) transactional expenses and (b) operating expenses, including administration fees, service and distribution fees, and other Fund expenses. The expense examples shown below (which are based on a hypothetical investment of $1,000 invested on May 1, 2018 and held through October 31, 2018) are intended to assist shareholders both in calculating expenses based on an investment in each Fund and in comparing these expenses with similar costs of investing in other mutual funds.

The expense examples provide information about actual account values and actual expenses. In order to estimate the expenses a shareholder paid during the period covered by this report, shareholders can divide their account value by $1,000 and then multiply the result by the number corresponding to their Fund under the heading entitled “Expenses Paid During the Period.”

The expense examples also provide information about hypothetical account values and hypothetical expenses based on a Fund’s actual expense ratio and an assumed rate of return of 5% per year before expenses. In order to assist shareholders in comparing the ongoing expenses of investing in these Funds and other funds, compare the 5% hypothetical examples with the 5% hypothetical examples that appear in shareholder reports of other funds.

The expenses shown in the expense examples are intended to highlight shareholders’ ongoing costs only and do not reflect any transactional expenses, such as sales charges, if any. Therefore, the hypothetical examples are useful in comparing ongoing expenses only, and will not help shareholders determine the relative total expenses of owning different funds. If these transactional expenses were included, shareholder expenses would have been higher.

Expense Examples

	Actual						Hypothetical (b)
	Beginning Account Value (05/01/18)		Ending Account Value (10/31/18)		Expenses Paid During the Period (a)		Beginning Account Value (05/01/18)		Ending Account Value (10/31/18)		Expenses Paid During the Period (a)		Annualized Expense Ratio
BlackRock Premier Government Institutional Fund(c)	$	1,000.00	$	1,009.60	$	0.71	$	1,000.00	$	1,024.50	$	0.71		0.14	%
BlackRock Treasury Strategies Institutional Fund(c)		1,000.00		1,007.70		1.82		1,000.00		1,023.39		1.84		0.36	��
BlackRock Select Treasury Strategies Institutional Fund(c)		1,000.00		1,008.60		0.91		1,000.00		1,024.30		0.92		0.18
FFI Government Fund		1,000.00		1,007.00		2.73		1,000.00		1,022.48		2.75		0.54
FFI Treasury Fund		1,000.00		1,008.10		1.62		1,000.00		1,023.59		1.63		0.32

^(a)  Expenses for each Fund are equal to the annualized expense ratio, multiplied by the average account value over the period, multiplied by 184/365 (to reflect the one-half year period shown).

^(b)  Hypothetical 5% annual return before expenses is calculated by prorating the number of days in the most recent fiscal half year divided by 365.

^(c) Because the Funds invest all of their assets in their respective Master Portfolio, the expense example reflects the expenses of both the Funds and the Master Portfolios in which they invest.

6 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Schedule of Investments  (unaudited) October 31, 2018 FFI Government Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
U.S. Government Sponsored Agency Obligations(a) — 1.3%
Federal Home Loan Bank Discount Notes, 2.09%, 06/14/19	$	800	$	800,000
Total U.S. Government Sponsored Agency Obligations — 1.3% (Cost — $800,000)				800,000
U.S. Treasury Obligations(b) — 14.3%
U.S. Treasury Bills, 2.15%, 11/01/18		9,000		9,000,000
Total U.S. Treasury Obligations — 14.3% (Cost — $9,000,000)				9,000,000
Total Repurchase Agreements — 82.6%				52,000,000
Total Investments — 98.2% (Cost — $61,800,000*)				61,800,000
Other Assets Less Liabilities — 1.8%				1,149,972
Net Assets — 100.0%			$	62,949,972

* Cost for U.S. federal income tax purposes.

^(a)  Variable rate security. Rate shown is the rate in effect as of period end.

^(b)  Rates are discount rates or a range of discount rates as of period end.

Repurchase Agreements

	Repurchase Agreements												Collateral
Counterparty	Coupon Rate			Purchase Date		Maturity Date		Par (000)		At Value (000)		Proceeds Including Interest	Position	Original Par	Position Received, At Value
BNP Paribas Securities Corp.		2.21	%		10/31/18		11/01/18	$	8,000	$	8,000	$8,000,491	U.S. Government Sponsored Agency Obligations, 3.18% to 6.00% due 10/19/32 to 10/25/48	$55,308,770	$8,325,347
Citigroup Global Markets, Inc.		2.22			10/31/18		11/01/18		9,000		9,000	9,000,555	U.S. Treasury Obligation, 2.88%,due 10/31/23	9,207,400	9,180,054
HSBC Securities (USA), Inc.		2.21			10/31/18		11/01/18		10,000		10,000	10,000,614	U.S. Government Sponsored Agency Obligation, 4.50%, due 08/20/48	9,932,468	10,200,000
Merrill Lynch, Pierce, Fenner & Smith, Inc.		2.20			10/31/18		11/01/18		10,000		10,000	10,000,611	U.S. Treasury Obligations, 1.25% to 4.38%, due 06/30/19 to 11/15/39	9,285,900	10,200,078
		2.22			10/31/18		11/01/18		1,000		1,000	1,000,062	U.S. Government Sponsored Agency Obligation, 3.50%, due 02/20/48	1,036,145	1,020,000
Total Merrill Lynch, Pierce, Fenner & Smith, Inc.										$	11,000				$11,220,078
Mufg Securities Americas Inc.		2.20			10/31/18		11/01/18		1,000		1,000	1,000,061	U.S. Government Sponsored Agency Obligations, 4.00% to 4.50%, due 04/01/47 to 09/01/47	1,201,409	1,030,001
Natixis SA		2.19	(a)		10/31/18		11/01/18		3,000		3,000	3,000,183	U.S. Treasury Obligations, 0.00% to 3.13%, due 04/11/19 to 02/15/42	3,146,600	3,060,041
		2.21	(a)		10/31/18		11/01/18		1,000		1,000	1,000,061	U.S. Treasury Obligations, 0.00% to 6.00%, due 11/23/18 to 06/01/48	4,738,402	1,027,774
Total Natixis SA										$	4,000				$4,087,815
TD Securities (USA) LLC		2.21			10/31/18		11/01/18		9,000		9,000	9,000,553	U.S. Government Sponsored Agency Obligation, 3.50% due 07/01/46	12,049,041	9,270,000
										$	52,000				$53,313,295

^(a)  Variable rate security. Rate as of period end and maturity is the date the principal owed can be recovered through demand.

SCHEDULES OF INVESTMENTS 7

Schedule of Investments  (unaudited) (continued) October 31, 2018 FFI Government Fund

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of investments. For information about the Fund’s policy regarding valuation of investments, refer to the Notes to Financial Statements.

The following table summarizes the Fund’s investments categorized in the disclosure hierarchy:

	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Short-Term Securities(a)	$	—	$	61,800,000	$	—	$	61,800,000

^(a)  See above Schedule of Investments for values in each security type.

During the period ended October 31, 2018, there were no transfers between levels.

See notes to financial statements.

8 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Schedule of Investments  (unaudited) October 31, 2018 FFI Treasury Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
U.S. Treasury Obligations — 99.7%
U.S. Treasury Bills(a):
2.11%, 11/01/18	$	30,375	$	30,375,000
2.13%, 11/08/18		99,000		98,959,678
2.17%, 11/15/18		63,325		63,272,515
2.07%, 11/23/18		10,000		9,987,564
U.S. Treasury Notes:
1.13%, 02/28/19		495		493,191
2.75%, 02/15/19		5,000		5,007,474
(3 mo. Treasury money market yield + 0.07%), 2.38%, 04/30/19(b)		1,140		1,140,112
Total Investments — 99.7% (Cost — $209,235,534*)				209,235,534
Other Assets Less Liabilities — 0.3%				589,811
Net Assets — 100.0%			$	209,825,345

* Cost for U.S. federal income tax purposes.

^(a)  Rates are discount rates or a range of discount rates as of period end.

^(b)  Variable rate security. Rate shown is the rate in effect as of period end.

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of investments. For information about the Fund’s policy regarding valuation of investments, refer to the Notes to Financial Statements.

The following table summarizes the Fund’s investments categorized in the disclosure hierarchy:

	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Short-Term Securities(a)	$	—	$	209,235,534	$	—	$	209,235,534

^(a)  See above Schedule of Investments for values in each security type.

During the period ended October 31, 2018, there were no transfers between levels.

See notes to financial statements.

SCHEDULES OF INVESTMENTS 9

Statements of Assets and Liabilities  (unaudited)

October 31, 2018

	BlackRock Premier Government Institutional Fund		BlackRock Treasury Strategies Institutional Fund		BlackRock Select Treasury Strategies Institutional Fund		FFI Government Fund		FFI Treasury Fund
ASSETS
Investments at value — from the applicable Master Portfolio	$	127,045,293	$	217,915,029	$	181,383,749	$	—	$	—
Investments at value — unaffiliated(a)		—		—		—		9,800,000		209,235,534
Repurchase agreements at value — unaffiliated(b)		—		—		—		52,000,000		—
Cash		—		—		—		1,300,440		980,869
Receivables:
From the Administrator		110,456		7,804		556		—		—
Interest — unaffiliated		—		—		—		4,066		30,173
Prepaid expenses		12,710		18,038		7,412		11,113		10,613
Total assets		127,168,459		217,940,871		181,391,717		63,115,619		210,257,189
LIABILITIES
Payables:
Income dividend distributions		179,014		150,898		317,907		44,155		295,082
Transfer agent fees		47,893		47,379		16,694		—		—
Professional fees		37,598		22,865		27,608		33,805		33,129
Directors’ and Officer’s fees		78		61		79		1,796		2,107
Board realignment and consolidation		1,675		7,804		924		1,531		1,588
Investment advisory fees		—		—		—		10,744		37,240
Administration fees		—		28,191		1,901		—		—
Custodian fees		—		—		—		27,635		28,491
Other accrued expenses		8,055		6,952		6,315		45,981		34,207
Total liabilities		274,313		264,150		371,428		165,647		431,844
NET ASSETS	$	126,894,146	$	217,676,721	$	181,020,289	$	62,949,972	$	209,825,345
NET ASSETS CONSIST OF
Paid-in capital	$	126,828,635	$	217,539,643	$	180,930,097	$	62,943,489	$	209,815,419
Accumulated earnings		65,511		137,078		90,192		6,483		9,926
Net Assets, $1.00 net asset value per share(c)	$	126,894,146	$	217,676,721	$	181,020,289	$	62,949,972	$	209,825,345
(a) Investments at cost — unaffiliated	$	—	$	—	$	—	$	9,800,000	$	209,235,534
(b) Repurchase agreements at cost — unaffiliated	$	—	$	—	$	—	$	52,000,000	$	—
(c) Shares outstanding, unlimited shares authorized, par value $0.01 per share		126,828,635		217,539,643		180,930,070		62,943,489		209,815,428

See notes to financial statements.

10 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Statements of Operations  (unaudited)

Six Months Ended October 31, 2018

	BlackRock Premier Government Institutional Fund			BlackRock Treasury Strategies Institutional Fund			BlackRock Select Treasury Strategies Institutional Fund			FFI Government Fund			FFI Treasury Fund
INVESTMENT INCOME
Interest — unaffiliated	$	—		$	—		$	—		$	652,519		$	2,208,750
Net investment income allocated from the applicable Master Portfolio:
Interest — unaffiliated		2,058,338			2,299,773			1,982,583			—			—
Expenses		(113,181	)		(104,125	)		(89,494	)		—			—
Fees waived		—			1,255			1,101			—			—
Total investment income		1,945,157			2,196,903			1,894,190			652,519			2,208,750
FUND EXPENSES
Investment advisory		—			—			—			120,018			404,421
Administration		115,492			184,164			137,509			—			—
Transfer agent		122,518			88,803			63,432			34,939			70,316
Registration		30,515			28,289			18,989			11,150			12,002
Professional		24,878			15,583			16,509			23,773			23,901
Rating Agency		—			11,417			15,135			218			966
Printing		3,082			2,961			2,832			3,208			5,096
Custodian		—			—			—			19,799			5,299
Accounting services		—			—			—			11,457			11,673
Directors and Officer		—			34			—			5,401			5,911
Board realignment and consolidation		1,494			7,804			786			1,369			1,418
Miscellaneous		6,532			5,464			4,543			3,867			4,999
Total expenses		304,511			344,519			259,735			235,199			546,002
Less fees waived and/or reimbursed by the Manager		—			—			—			(51,436	)		(173,324	)
Less fees waived and/or reimbursed by the Administrator		(252,851	)		(7,804	)		(156,550	)		—			—
Total expenses after fees waived and/or reimbursed		51,660			336,715			103,185			183,763			372,678
Net investment income		1,893,497			1,860,188			1,791,005			468,756			1,836,072
REALIZED GAIN
Net realized gain allocated from the applicable Master Portfolio		—			418			352			—			—
Net realized gain from investments		—			—			—			—			1,269
NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS	$	1,893,497		$	1,860,606		$	1,791,357		$	468,756		$	1,837,341

See notes to financial statements.

FINANCIAL STATEMENTS 11

Statements of Changes in Net Assets

	BlackRock Premier Government Institutional Fund						BlackRock Treasury Strategies Institutional Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended 04/30/18			Six Months Ended 10/31/18 (unaudited)			Year Ended 04/30/18
INCREASE (DECREASE) IN NET ASSETS
OPERATIONS
Net investment income	$	1,893,497		$	14,494,844		$	1,860,188		$	5,134,063
Net realized gain		—			68,084			418			81,067
Net increase in net assets resulting from operations		1,893,497			14,562,928			1,860,606			5,215,130
DISTRIBUTIONS TO SHAREHOLDERS(a)(b)
Decrease in net assets resulting from distributions to shareholders		(2,143,497	)		(14,549,695	)		(1,860,484	)		(5,134,063	)
CAPITAL SHARE TRANSACTIONS
Proceeds from sale of shares .		—			6,976,550,442			—			640,801,896
Reinvestment of distributions		2,222,752			5,798,839			1,828,782			3,706,680
Cost of shares redeemed		(214,361,913	)		(9,200,919,504	)		(56,010,606	)		(1,317,239,083	)
Net decrease in net assets derived from capital share transactions		(212,139,161	)		(2,218,570,223	)		(54,181,824	)		(672,730,507	)
NET ASSETS(b)
Total decrease in net assets		(212,389,161	)		(2,218,556,990	)		(54,181,702	)		(672,649,440	)
Beginning of period		339,283,307			2,557,840,297			271,858,423			944,507,863
End of period	$	126,894,146		$	339,283,307		$	217,676,721		$	271,858,423

^(a)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(b)  Prior year distribution character information and undistributed net investment income has been modified or removed to conform with current year Regulation S-X presentation changes. Refer to Note 9 for this prior year information.

See notes to financial statements.

12 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Statements of Changes in Net Assets  (continued)

	BlackRock Select Treasury Strategies Institutional Fund						FFI Government Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended 04/30/18			Six Months Ended 10/31/18 (unaudited)			Year Ended 04/30/18
INCREASE (DECREASE) IN NET ASSETS
OPERATIONS
Net investment income	$	1,791,005		$	4,097,522		$	468,756		$	594,422
Net realized gain		352			74,424			—			1,704
Net increase in net assets resulting from operations		1,791,357			4,171,946			468,756			596,126
DISTRIBUTIONS TO SHAREHOLDERS(a)(b)
Decrease in net assets resulting from distributions to shareholders		(1,790,711	)		(4,097,522	)		(468,756	)		(594,422	)
CAPITAL SHARE TRANSACTIONS
Proceeds from sale of shares		—			805,131,106			—			—
Reinvestment of distributions		1,736,197			1,775,348			436,068			570,859
Cost of shares redeemed		(56,566,211	)		(935,353,482	)		(12,665,799	)		(32,773,864	)
Net decrease in net assets derived from capital share transactions		(54,830,014	)		(128,447,028	)		(12,229,731	)		(32,203,005	)
NET ASSETS(b)
Total decrease in net assets		(54,829,368	)		(128,372,604	)		(12,229,731	)		(32,201,301	)
Beginning of period		235,849,657			364,222,261			75,179,703			107,381,004
End of period	$	181,020,289		$	235,849,657		$	62,949,972		$	75,179,703

^(a)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(b)  Prior year distribution character information and undistributed net investment income has been modified or removed to conform with current year Regulation S-X presentation changes. Refer to Note 9 for this prior year information.

See notes to financial statements.

FINANCIAL STATEMENTS 13

Statements of Changes in Net Assets  (continued)

	FFI Treasury Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended 04/30/18
INCREASE (DECREASE) IN NET ASSETS
OPERATIONS
Net investment income	$	1,836,072		$	3,123,077
Net realized gain		1,269			6,225
Net increase in net assets resulting from operations		1,837,341			3,129,302
DISTRIBUTIONS TO SHAREHOLDERS(a)(b)
Decrease in net assets resulting from distributions to shareholders		(1,836,072	)		(3,123,619	)
CAPITAL SHARE TRANSACTIONS
Reinvestment of distributions		1,774,783			2,969,166
Cost of shares redeemed		(29,561,724	)		(300,250,842	)
Net decrease in net assets derived from capital share transactions		(27,786,941	)		(297,281,676	)
NET ASSETS(b)
Total decrease in net assets		(27,785,672	)		(297,275,993	)
Beginning of period		237,611,017			534,887,010
End of period	$	209,825,345		$	237,611,017

^(a)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(b)  Prior year distribution character information and undistributed net investment income has been modified or removed to conform with current year Regulation S-X presentation changes. Refer to Note 9 for this prior year information.

See notes to financial statements.

14 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Financial Highlights  

(For a share outstanding throughout each period)

	BlackRock Premier Government Institutional Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended April 30,
				2018			2017			2016			2015			2014
Net asset value, beginning of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Net investment income		0.0096			0.0097			0.0031			0.0012			0.0007			0.0008
Net realized gain		—			0.0000	(a)		0.0002			0.0001			0.0001			0.0000	(a)
Net increase from investment operations		0.0096			0.0097			0.0033			0.0013			0.0008			0.0008
Distributions(b)
From net investment income		(0.0096	)		(0.0097	)		(0.0031	)		(0.0012	)		(0.0007	)		(0.0008	)
From net realized gain		—			(0.0000	)(c)		(0.0002	)		(0.0001	)		(0.0001	)		—
Total distributions		(0.0096	)		(0.0097	)		(0.0033	)		(0.0013	)		(0.0008	)		(0.0008	)
Net asset value, end of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Total Return(d)
Based on net asset value		0.96	%(e)		0.97	%		0.33	%		0.13	%		0.08	%		0.08	%
Ratios to Average Net Assets(f)
Total expenses		0.36	%(g)		0.20	%		0.18	%		0.17	%		0.17	%		0.17	%
Total expenses after fees waived and/or reimbursed and paid indirectly		0.14	%(g)		0.14	%		0.15	%		0.17	%		0.17	%		0.17	%
Net investment income		1.64	%(g)		0.85	%		0.31	%		0.12	%		0.07	%		0.08	%
Supplemental Data
Net assets, end of period (000)	$	126,894		$	339,283		$	2,557,840		$	3,170,211		$	3,441,012		$	6,613,656

^(a)  Amount is less than $0.00005 per share.

^(b)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(c)  Amount is greater than $(0.00005) per share.

^(d)  Where applicable, assumes the reinvestment of distributions.

^(e)  Aggregate total return.

^(f)  Includes the Fund’s share of Master Premier Government Institutional Portfolio’s allocated expenses and/or net investment income.

^(g)  Annualized.

See notes to financial statements.

FINANCIAL HIGHLIGHTS 15

Financial Highlights  (continued)

(For a share outstanding throughout each period)

	BlackRock Treasury Strategies Institutional Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended April 30,
				2018			2017			2016			2015			2014
Net asset value, beginning of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Net investment income		0.0077			0.0084			0.0016			0.0005			0.0004			0.0003
Net realized gain		0.0000	(a)		0.0000	(a)		0.0002			0.0000	(a)		0.0000	(a)		0.0000	(a)
Net increase from investment operations		0.0077			0.0084			0.0018			0.0005			0.0004			0.0003
Distributions(b)
From net investment income		(0.0077	)		(0.0084	)		(0.0016	)		(0.0005	)		(0.0004	)		(0.0003	)
From net realized gain		(0.0000	)(c)		(0.0000	)(c)		(0.0002	)		(0.0000	)(c)		(0.0000	)(c)		(0.0000	)(c)
Total distributions		(0.0077	)		(0.0084	)		(0.0018	)		(0.0005	)		(0.0004	)		(0.0003	)
Net asset value, end of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Total Return(d)
Based on net asset value		0.77	%(e)		0.85	%		0.18	%		0.05	%		0.04	%		0.03	%
Ratios to Average Net Assets(f)
Total expenses		0.36	%(g)		0.29	%		0.28	%		0.25	%		0.24	%		0.24	%
Total expenses after fees waived and/or reimbursed and paid indirectly		0.36	%(g)		0.29	%		0.28	%		0.23	%		0.20	%		0.20	%
Net investment income		1.52	%(g)		0.76	%		0.16	%		0.05	%		0.03	%		0.02	%
Supplemental Data
Net assets, end of period (000)	$	217,677		$	271,858		$	944,508		$	1,343,275		$	1,700,011		$	1,931,574

^(a)  Amount is less than $0.00005 per share.

^(b)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(c)  Amount is greater than $(0.00005) per share.

^(d)  Where applicable, assumes the reinvestment of distributions.

^(e)  Aggregate total return.

^(f)  Includes the Fund’s share of Master Treasury Strategies Institutional Portfolio’s allocated expenses and/or net investment income.

^(g)  Annualized.

See notes to financial statements.

16 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Financial Highlights  (continued)

(For a share outstanding throughout each period)

	BlackRock Select Treasury Strategies Institutional Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended April 30,
				2018			2017			2016			2015			2014
Net asset value, beginning of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Net investment income		0.0086			0.0096			0.0026			0.0011			0.0005			0.0005
Net realized gain		0.0000	(a)		0.0000	(a)		0.0004			0.0000	(a)		0.0000	(a)		0.0000	(a)
Net increase from investment operations		0.0086			0.0096			0.0030			0.0011			0.0005			0.0005
Distributions(b)
From net investment income		(0.0086	)		(0.0096	)		(0.0026	)		(0.0011	)		(0.0005	)		(0.0005	)
From net realized gain		—			(0.0000	)(c)		(0.0004	)		(0.0000	)(c)		(0.0000	)(c)		(0.0000	)(c)
Total distributions		(0.0086	)		(0.0096	)		(0.0030	)		(0.0011	)		(0.0005	)		(0.0005	)
Net asset value, end of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Total Return(d)
Based on net asset value		0.86	%(e)		0.96	%		0.30	%		0.11	%		0.05	%		0.05	%
Ratios to Average Net Assets(f)
Total expenses		0.33	%(g)		0.24	%		0.22	%		0.21	%		0.20	%		0.20	%
Total expenses after fees waived and/or reimbursed and paid indirectly		0.18	%(g)		0.18	%		0.18	%		0.18	%		0.18	%		0.18	%
Net investment income		1.69	%(g)		0.91	%		0.24	%		0.10	%		0.05	%		0.04	%
Supplemental Data
Net assets, end of period (000)	$	181,020		$	235,850		$	364,222		$	1,035,438		$	1,774,179		$	2,593,125

^(a)  Amount is less than $0.00005 per share.

^(b)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(c)  Amount is greater than $(0.00005) per share.

^(d)  Where applicable, assumes the reinvestment of distributions.

^(e)  Aggregate total return.

^(f)  Includes the Fund’s share of Master Treasury Strategies Institutional Portfolio’s allocated expenses and/or net investment income.

^(g)  Annualized.

See notes to financial statements.

FINANCIAL HIGHLIGHTS 17

Financial Highlights  (continued)

(For a share outstanding throughout each period)

	FFI Government Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended April 30,
				2018			2017			2016			2015			2014
Net asset value, beginning of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Net investment income		0.0069			0.0069			0.0010			0.0004			0.0001			0.0001
Net realized and unrealized gain		—			0.0000	(a)		0.0004			0.0000	(a)		0.0000	(a)		0.0000	(a)
Net increase from investment operations		0.0069			0.0069			0.0014			0.0004			0.0001			0.0001
Distributions(b)
From net investment income		(0.0069	)		(0.0069	)		(0.0010	)		(0.0004	)		(0.0001	)		(0.0001	)
From net realized gain		—			(0.0000	)(c)		(0.0004	)		(0.0000	)(c)		(0.0000	)(c)		(0.0000	)(c)
Total distributions		(0.0069	)		(0.0069	)		(0.0014	)		(0.0004	)		(0.0001	)		(0.0001	)
Net asset value, end of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Total Return(d)
Based on net asset value		0.70	%(e)		0.69	%		0.14	%		0.04	%		0.01	%		0.01	%
Ratios to Average Net Assets
Total expenses		0.69	%(f)		0.61	%		0.48	%		0.38	%		0.37	%		0.36	%
Total expenses after fees waived and/or reimbursed and paid indirectly		0.54	%(f)		0.46	%		0.30	%		0.18	%		0.10	%		0.10	%
Net investment income		1.37	%(f)		0.67	%		0.10	%		0.04	%		0.01	%		0.01	%
Supplemental Data
Net assets, end of period (000)	$	62,950		$	75,180		$	107,381		$	975,801		$	1,194,071		$	1,666,365

^(a)  Amount is less than $0.00005 per share.

^(b)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(c)  Amount is greater than $(0.00005) per share.

^(d)  Where applicable, assumes the reinvestment of distributions.

^(e)  Aggregate total return.

^(f)  Annualized.

See notes to financial statements.

18 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Financial Highlights  (continued)

(For a share outstanding throughout each period)

	FFI Treasury Fund
	Six Months Ended 10/31/18 (unaudited)			Year Ended April 30,
				2018			2017			2016			2015			2014
Net asset value, beginning of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Net investment income		0.0080			0.0087			0.0014			0.0003			0.0000	(a)		0.0000	(a)
Net realized and unrealized gain		0.0000	(a)		0.0000	(a)		0.0003			0.0000	(a)		0.0001			0.0001
Net increase from investment operations		0.0080			0.0087			0.0017			0.0003			0.0001			0.0001
Distributions(b)
From net investment income		(0.0080	)		(0.0087	)		(0.0014	)		(0.0003	)		(0.0000	)(c)		(0.0000	)(c)
From net realized gain		(0.0000	)(c)		(0.0000	)(c)		(0.0003	)		(0.0000	)(c)		(0.0001	)		(0.0001	)
Total distributions		(0.0080	)		(0.0087	)		(0.0017	)		(0.0003	)		(0.0001	)		(0.0001	)
Net asset value, end of period	$	1.00		$	1.00		$	1.00		$	1.00		$	1.00		$	1.00
Total Return(d)
Based on net asset value		0.81	%(e)		0.88	%		0.17	%		0.03	%		0.01	%		0.01	%
Ratios to Average Net Assets
Total expenses		0.47	%(f)		0.41	%		0.39	%		0.36	%		0.35	%		0.34	%
Total expenses after fees waived and/or reimbursed and paid indirectly		0.32	%(f)		0.26	%		0.25	%		0.11	%		0.04	%		0.05	%
Net investment income		1.59	%(f)		0.82	%		0.11	%		0.02	%		0.00	%		0.00	%
Supplemental Data
Net assets, end of period (000)	$	209,825		$	237,611		$	534,887		$	1,437,009		$	1,756,039		$	2,129,423

^(a)  Amount is less than $0.00005 per share.

^(b)  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

^(c)  Amount is greater than $(0.00005) per share.

^(d)  Where applicable, assumes the reinvestment of distributions.

^(e)  Aggregate total return.

^(f)  Annualized.

See notes to financial statements.

FINANCIAL HIGHLIGHTS 19

Notes to Financial Statements  (unaudited) Funds for Institutions Series

1. ORGANIZATION

Funds For Institutions Series (the “Trust”) is registered under the Investment Company Act of 1940, as amended (the “1940 Act”), as an open-end management investment company. The Trust is organized as a Massachusetts business trust. The Trust consists of five series, BlackRock Premier Government Institutional Fund (“Premier Government Institutional Fund”), BlackRock Treasury Strategies Institutional Fund (“Treasury Strategies Institutional Fund”), BlackRock Select Treasury Strategies Institutional Fund (“Select Treasury Strategies Institutional Fund”), FFI Government Fund (“Government Fund”) and FFI Treasury Fund (“Treasury Fund”) (collectively, the “Funds” or individually a “Fund”). Each Fund is classified as diversified. Premier Government Institutional Fund, Treasury Strategies Institutional Fund and Select Treasury Strategies Institutional Fund (the “Feeder Funds”) seek to achieve their investment objectives by investing all of their assets in the applicable series (collectively, the “Master Portfolios” or individually, a “Master Portfolio”) of Master Institutional Money Market LLC (the “Master LLC”), which have the same investment objective and strategies as the corresponding Feeder Funds. Premier Government Institutional Fund invests all of its assets in Master Premier Government Institutional Portfolio. Treasury Strategies Institutional Fund and Select Treasury Strategies Institutional Fund invest all of their assets in Master Treasury Strategies Institutional Portfolio. The Master LLC is organized as a Delaware limited liability company and is a registered investment company. The value of each Feeder Fund’s investment in the corresponding Master Portfolio reflects the Feeder Fund’s proportionate interest in the net assets of the corresponding Master Portfolio. At October 31, 2018, the percentage of Master Premier Government Institutional Portfolio owned by Premier Government Institutional Fund was 100%. At October 31, 2018, the percentages of Master Treasury Strategies Institutional Portfolio owned by Treasury Strategies Institutional Fund and Select Treasury Strategies Institutional Fund were 55% and 45%, respectively. The performance of each Feeder Fund is directly affected by the performance of the corresponding Master Portfolio. The financial statements of the Master Portfolios, including their Schedules of Investments, are included elsewhere in this report and should be read in conjunction with the Feeder Funds’ financial statements.

The Board of Trustees of the Trust and the Board of Directors of the Master LLC are referred to throughout this report as the “Board of Directors” or the “Board” and the Trustees of the Trust and the Directors of the Master LLC are referred to throughout this report as the “Directors”.

Effective December 1, 2017, Premier Government Institutional Fund, Treasury Strategies Institutional Fund and Select Treasury Strategies Institutional Fund no longer accept purchase orders.

Effective September 1, 2016, Government Fund and Treasury Fund no longer accept purchase orders.

Each Fund operates as a “government money market fund” under Rule 2a-7 under the 1940 Act. Each Fund is not subject to liquidity fees or temporary suspensions of redemptions due to declines in a Fund’s weekly liquid assets.

The Funds, together with certain other registered investment companies advised by BlackRock Advisors, LLC (the “Manager”) or its affiliates, are included in a complex of open-end funds referred to as the Equity-Liquidity Complex.

2. SIGNIFICANT ACCOUNTING POLICIES

The financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”), which may require management to make estimates and assumptions that affect the reported amounts of assets and liabilities in the financial statements, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of increases and decreases in net assets from operations during the reporting period. Actual results could differ from those estimates. Each Fund is considered an investment company under U.S. GAAP and follows the accounting and reporting guidance applicable to investment companies. Below is a summary of significant accounting policies:

Investment Transactions and Income Recognition:

For financial reporting purposes, investment transactions are recorded on the dates the transactions are entered into (the “trade dates”). Realized gains and losses on investment transactions are determined on the identified cost basis. Interest income, including amortization and accretion of premiums and discounts on debt securities, is recognized on an accrual basis. For the Feeder Funds, for financial reporting purposes, contributions to and withdrawals from the Master Portfolio are accounted for on a trade date basis. The Feeder Funds record their proportionate share of the Master Portfolio’s income, expenses and realized and unrealized gains and losses on a daily basis. In addition, the Feeder Funds accrue their own expenses.

Distributions: Distributions from net investment income are declared daily and paid monthly. Distributions of capital gains are recorded on the ex-dividend date and made at least annually. The character and timing of distributions are determined in accordance with U.S. federal income tax regulations, which may differ from U.S. GAAP.

Recent Accounting Standards: In March 2017, the Financial Accounting Standards Board issued Accounting Standards Update “Premium Amortization of Purchased Callable Debt Securities” which amends the amortization period for certain purchased callable debt securities. Under the new guidance, the premium amortization of purchased callable debt securities that have explicit, non-contingent call features and are callable at fixed prices will be amortized to the earliest call date. The guidance will be applied on a modified retrospective basis and is effective for fiscal years, and their interim periods, beginning after December 15, 2018. Management is currently evaluating the impact of this guidance to the Funds.

In August 2018, the Financial Accounting Standards Board issued Accounting Standards Update 2018-13 “Changes to the Disclosure Requirements for Fair Value Measurement” which modifies disclosure requirements for fair value measurements. The guidance is effective for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. Management is currently evaluating the impact of this guidance to the Funds.

Indemnifications: In the normal course of business, a Fund enters into contracts that contain a variety of representations that provide general indemnification. A Fund’s maximum exposure under these arrangements is unknown because it involves future potential claims against a Fund, which cannot be predicted with any certainty.

Other: Expenses directly related to a Fund are charged to that Fund. Other operating expenses shared by several funds, including other funds managed by the Manager, are prorated among those funds on the basis of relative net assets or other appropriate methods.

20 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Notes to Financial Statements  (unaudited) (continued) Funds for Institutions Series

3. INVESTMENT VALUATION AND FAIR VALUE MEASUREMENTS

Investment Valuation Policies: U.S. GAAP defines fair value as the price the Funds would receive to sell an asset or pay to transfer a liability in an orderly transaction between market participants at the measurement date. Each Fund records its investment in the Master Portfolio at fair value based on the Fund’s proportionate interest in the net assets of the Master Portfolio. Valuation of securities held by the Master Portfolio is discussed in Note 3 of the Master Portfolio’s Notes to Financial Statements, which are included elsewhere in this report. Government Fund’s and Treasury Fund’s investments are valued under the amortized cost method which approximates current market value in accordance with Rule 2a-7 under the 1940 Act. Under this method, investments are valued at cost when purchased and, thereafter, a constant proportionate accretion of discounts and amortization of premiums are recorded until the maturity of the security. Each Fund seeks to maintain its net asset value (“NAV”) per share at $1.00, although there is no assurance that it will be able to do so on a continuing basis.

Fair Value Hierarchy: Various inputs are used in determining the fair value of investments. These inputs to valuation techniques are categorized into a fair value hierarchy consisting of three broad levels for financial statement purposes as follows:

• Level 1 — Unadjusted price quotations in active markets/exchanges for identical assets or liabilities that each Fund has the ability to access

• Level 2 — Other observable inputs (including, but not limited to, quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market–corroborated inputs)

• Level 3 — Unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including each Fund’s own assumptions used in determining the fair value of investments)

The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Accordingly, the degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3. The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the fair value hierarchy classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety.

Changes in valuation techniques may result in transfers into or out of an assigned level within the hierarchy. In accordance with each Fund’s policy, transfers between different levels of the fair value hierarchy are deemed to have occurred as of the beginning of the reporting period. The categorization of a value determined for investments is based on the pricing transparency of the investments and is not necessarily an indication of the risks associated with investing in those securities.

4. SECURITIES AND OTHER INVESTMENTS

Repurchase Agreements: Repurchase agreements are commitments to purchase a security from a counterparty who agrees to repurchase the same security at a mutually agreed upon date and price. On a daily basis, the counterparty is required to maintain eligible collateral subject to the agreement and in value no less than the agreed upon repurchase amount. Pursuant to the custodial undertaking associated with a tri-party repurchase arrangement, an unaffiliated third party custodian maintains accounts to hold collateral for a fund and its counterparties. Typically, a fund and counterparty are not permitted to sell, re-pledge or use the collateral absent a default by the counterparty or a fund, respectively. A fund, along with other registered investment companies advised by the Manager, may transfer uninvested cash into a single joint trading account which is then invested in one or more repurchase agreements. As of period end, there were no joint trading accounts invested in repurchase agreements.

In the event the counterparty defaults and the fair value of the collateral declines, a fund could experience losses, delays and costs in liquidating the collateral.

Repurchase agreements are entered into by a fund under Master Repurchase Agreements (each, an “MRA”). The MRA permits a fund, under certain circumstances including an event of default (such as bankruptcy or insolvency), to offset payables and/or receivables with collateral held by and/or posted to the counterparty. As a result, one single net payment is created. Bankruptcy or insolvency laws of a particular jurisdiction may impose restrictions on or prohibitions against such a right of offset in the event of the MRA counterparty’s bankruptcy or insolvency. Based on the terms of the MRA, a fund receives securities as collateral with a market value in excess of the repurchase price at maturity. Upon a bankruptcy or insolvency of the MRA counterparty, a fund would recognize a liability with respect to such excess collateral. The liability reflects a fund’s obligation under bankruptcy law to return the excess to the counterparty.

5. INVESTMENT ADVISORY/ADMINISTRATION AGREEMENT AND OTHER TRANSACTIONS WITH AFFILIATES

The PNC Financial Services Group, Inc. is the largest stockholder and an affiliate of BlackRock, Inc. (“BlackRock”) for 1940 Act purposes.

Investment Advisory/Administration: The Trust, on behalf of each of Government Fund and Treasury Fund, entered into Investment Advisory Agreements with the Manager, the Funds’ investment adviser, and an indirect, wholly-owned subsidiary of BlackRock, to provide investment advisory and administrative services. The Manager is responsible for the management of Government Fund’s and Treasury Fund’s portfolio and provides the personnel, facilities, equipment and certain other services necessary to the operations of each Fund.

For such services, Government Fund and Treasury Fund pay the Manager a monthly fee at an annual rate equal to the following percentages of the average daily value of each Fund’s net assets:

Average Daily Net Assets	Investment Advisory Fees
First $500 Million		0.350	%
$500 Million — $750 Million		0.335
$750 Million — $1 Billion		0.320
Greater than $1 Billion		0.300

NOTESTO FINANCIAL STATEMENTS 21

Notes to Financial Statements  (unaudited) (continued) Funds for Institutions Series

The Trust, on behalf of the Feeder Funds entered into an Administration Agreement with BlackRock Advisors, LLC (the “Administrator), an indirect, wholly-owned subsidiary of BlackRock, to provide administrative services (other than investment advice and related portfolio activities).

For such services, the Feeder Funds pay the Manager a monthly fee at an annual rate equal to the following percentages of the average daily net assets of each Feeder Fund as follows.

	Administration Fees
Premier Government Institutional Fund		0.10	%
Treasury Strategies Institutional Fund		0.15
Select Treasury Strategies Institutional Fund		0.13

The Feeder Funds do not pay an investment advisory fee or investment management fee.

Distribution Fees: The Trust, on behalf of the Funds, entered into a Distribution Agreement with BlackRock Investments, LLC (“BRIL”), an affiliate of the Manager. There are no fees payable by the Funds pursuant to the Distribution Agreement

Expense Limitations, Waivers and Reimbursements: With respect to Government Fund and Treasury Fund, the Manager contractually agreed to waive a portion of the investment advisory fees through August 31, 2019, so that the annual investment advisory fee rate for each Fund was 0.20% of the Fund’s average daily net assets. The agreement may be terminated with respect to each Fund upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the applicable Fund. These amounts are included in fees waived and/or reimbursed by the Manager in the Statements of Operations.

For the six months ended October 31, 2018, the amounts waived and/or reimbursed by the Manager pursuant to these arrangements were as follows:

Government Fund	$	51,436
Treasury Fund	$	173,324

The Funds have begun to incur expenses in connection with a proposed realignment and consolidation of the boards of directors of certain BlackRock-advised funds. The Administrator has voluntarily agreed to reimburse Treasury Strategies Institutional Fund for all or a portion of such expenses, which amounts are included in fees waived and/or reimbursed by the Administrator in the Statements of Operations. For the six months ended October 31, 2018, the amount reimbursed was $7,804.

Under Select Treasury Strategies Institutional Fund’s administration agreement, in exchange for the administration fee, the Administrator has agreed to pay all other ordinary expenses of Select Treasury Strategies Institutional Fund other than the Fund’s pro rata portion of the investment advisory fee of Master Treasury Strategies Institutional Portfolio so that the Fund’s total annual operating expenses minus extraordinary expenses, if any, shall be no greater than 0.18% of the Fund’s average daily net assets. In the event that the Administrator does not pay such expenses of the Fund, the administration fee shall be automatically reduced by an amount equal to the amount of such expenses not paid by the Administrator. The Administrator has also voluntarily agreed to waive its administration fees by the amount of administration fees to enable the Fund that invests in Master Treasury Strategies Institutional Portfolio to maintain minimum levels of daily net investment income if applicable. The Administrator may discontinue the voluntary waiver at any time. For the six months ended October 31, 2018, $156,550 was waived pursuant to these agreements. These amounts are included in fees waived and/or reimbursed by the Administrator in the Statements of Operations.

With respect to Premier Government Institutional Fund, the Administrator has contractually agreed to waive and/or reimburse fees and expenses of the Fund through August 31, 2019, so that the Fund’s total annual operating expenses, excluding interest expense, dividend expense, tax expense, acquired fund fees and expenses, and certain other fund expenses, which constitute extraordinary expenses not incurred in the ordinary course of the Fund’s business, if any, shall be no greater than 0.14% of the Fund’s average daily net assets. The agreement may be terminated with respect to the Fund upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund. The Administrator has also voluntarily agreed to waive its administration fees by the amount of administration fees to enable the Fund that invests in Master Premier Government Institutional Portfolio to maintain minimum levels of daily net investment income if applicable. The Administrator may discontinue the voluntary waiver at any time. For the six months ended October 31, 2018, $252,851 was waived pursuant to these agreements. This amount is included in fees waived and/or reimbursed by the Administrator in the Statements of Operations.

Interfund Lending: In accordance with an exemptive order (the “Order”) from the U.S. Securities and Exchange Commission (“SEC”), Premier Government Institutional Fund, Treasury Strategies Institutional Fund and Select Treasury Strategies Institutional Fund may participate in a joint lending and borrowing facility for temporary purposes (the “Interfund Lending Program”), subject to compliance with the terms and conditions of the Order, and to the extent permitted by each Fund’s investment policies and restrictions. Each Fund is currently permitted to borrow under the Interfund Lending Program.

A lending BlackRock fund may lend in aggregate up to 15% of its net assets, but may not lend more than 5% of its net assets to any one borrowing fund through the Interfund Lending Program. A borrowing BlackRock fund may not borrow through the Interfund Lending Program or from any other source more than 33 1/3% of its total assets (or any lower threshold provided for by the fund’s investment restrictions). If a borrowing BlackRock fund’s total outstanding borrowings exceed 10% of its total assets, each of its outstanding interfund loans will be subject to collateralization of at least 102% of the outstanding principal value of the loan. All interfund loans are for temporary or emergency purposes and the interest rate to be charged will be the average of the highest current overnight repurchase agreement rate available to a lending fund and the bank loan rate, as calculated according to a formula established by the Board.

During the six months ended October 31, 2018, the Funds did not participate in the Interfund Lending Program.

Directors and Officers: Certain directors and/or officers of the Trust are directors and/or officers of BlackRock or its affiliates. Each Fund reimburses the Manager for a portion of the compensation paid to the Trust’s Chief Compliance Officer, which is included in Directors and Officer in the Statements of Operations.

22 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Notes to Financial Statements  (unaudited) (continued) Funds for Institutions Series

6. INCOME TAX INFORMATION

It is each Fund’s policy to comply with the requirements of the Internal Revenue Code of 1986, as amended, applicable to regulated investment companies, and to distribute substantially all of its taxable income to its shareholders. Therefore, no U.S. federal income tax provision is required.

Each Fund files U.S. federal and various state and local tax returns. No income tax returns are currently under examination. The statute of limitations on each Fund’s U.S. federal tax returns generally remains open for each of the four years ended April 30, 2018. The statutes of limitations on each Fund’s state and local tax returns may remain open for an additional year depending upon the jurisdiction.

Management has analyzed tax laws and regulations and their application to the Funds as of October 31, 2018, inclusive of the open tax return years, and does not believe that there are any uncertain tax positions that require recognition of a tax liability in the Funds’ financial statements.

7. PRINCIPAL RISKS

In the normal course of business, the Funds invest in securities or other instruments and may enter into certain transactions, and such activities subject each Fund to various risks, including among others, fluctuations in the market (market risk) or failure of an issuer to meet all of its obligations. The value of securities or other instruments may also be affected by various factors, including, without limitation: (i) the general economy; (ii) the overall market as well as local, regional or global political and/or social instability; (iii) regulation, taxation or international tax treaties between various countries; or (iv) currency, interest rate and price fluctuations. Each Fund’s prospectus provides details of the risks to which each Fund is subject.

Counterparty Credit Risk: The Funds may be exposed to counterparty credit risk, or the risk that an entity may fail to or be unable to perform on its commitments related to unsettled or open transactions. The Funds manage counterparty credit risk by entering into transactions only with counterparties that the Manager believes have the financial resources to honor their obligations and by monitoring the financial stability of those counterparties. Financial assets, which potentially expose the Funds to market, issuer and counterparty credit risks, consist principally of financial instruments and receivables due from counterparties. The extent of the Funds’ exposure to market, issuer and counterparty credit risks with respect to these financial assets is approximately their value recorded in the Statements of Assets and Liabilities, less any collateral held by the Funds.

8. CAPITAL SHARE TRANSACTIONS

The number of shares sold, reinvested and redeemed corresponds to the net proceeds from the sale of shares, reinvestment of all distributions and cost of shares redeemed, respectively, since shares are sold and redeemed at $1.00 per share.

9. REGULATION S-X AMENDMENTS

On August 17, 2018, the SEC adopted amendments to certain disclosure requirements in Securities Act Release No. 33-10532, Disclosure Update and Simplification. The Fund has adopted the amendments pertinent to Regulation S-X in this shareholder report. The amendments impacted certain disclosure presentation on the Statements of Assets and Liabilities, Statements of Changes in Net Assets and Notes to Financial Statements.

Prior year distribution information and undistributed net investment income in the Statements of Changes in Net Assets has been modified to conform to the current year presentation in accordance with the Regulation S-X changes.

Distributions for the year ended April 30, 2018 were classified as follows:

	Net Investment Income		Net Realized Gain
BlackRock Premier Government Institutional Fund	$	14,428,765	$	120,930
BlackRock Treasury Strategies Institutional Fund		5,123,664		10,399
BlackRock Select Treasury Strategies Institutional Fund		4,087,436		10,086
FFI Government Fund		592,137		2,285
FFI Treasury Fund		3,120,623		2,996

Undistributed net investment income as of April 30, 2018 is as follows:

	Undistributed net investment income
BlackRock Premier Government Institutional Fund	$	247,427
BlackRock Treasury Strategies Institutional Fund		55,889
BlackRock Select Treasury Strategies Institutional Fund		15,122
FFI Government Fund		4,779
FFI Treasury Fund		2,454

10. SUBSEQUENT EVENTS

Management has evaluated the impact of all subsequent events on the Funds through the date the financial statements were issued and has determined that there were no subsequent events requiring adjustment or additional disclosure in the financial statements.

NOTESTO FINANCIAL STATEMENTS 23

Master Portfolio Information  as of October 31, 2018 Master Institutional Money Market LLC

Portfolio Composition

Master Premier Government Institutional Portfolio	Percent of Net Assets
Repurchase Agreements		65	%
U.S. Treasury Obligations		27
Other Assets Less Liabilities		8

Master Treasury Strategies Institutional Portfolio	Percent of Net Assets
U.S. Treasury Obligations		100	%

24 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Schedule of Investments  (unaudited) October 31, 2018 Master Premier Government Institutional Portfolio (Percentages shown are based on Net Assets)

Security	Par (000)		Value
U.S. Treasury Obligations — 27.6%
U.S. Treasury Bills(a):
2.15%, 11/01/18	$	15,000	$	15,000,000
2.21%, 12/11/18		20,000		19,951,711
Total U.S. Treasury Obligations — 27.6 (Cost — $34,951,711)				34,951,711
Total Repurchase Agreements — 64.5% (Cost — $82,000,000)				82,000,000
Total Investments — 92.1% (Cost — $116,951,711*)				116,951,711
Other Assets Less Liabilities — 7.9%				10,093,582
Net Assets — 100.0%			$	127,045,293

* Cost for U.S. federal income tax purposes.

^(a)  Rates are discount rates or a range of discount rates as of period end.

Repurchase Agreements

	Repurchase Agreements												Collateral
Counterparty	Coupon Rate			Purchase Date		Maturity Date		Par (000)		At Value (000)		Proceeds Including Interest	Position	Original Par	Position Received, At Value
BNP Paribas Securities Corp.		2.19	%		10/31/18		11/01/18	$	15,000	$	15,000	$15,000,913	U.S. Treasury Obligations, 0.00% to 2.88%, due 10/31/19 to 5/15/45	$15,696,536	$15,300,059
BNP Paribas Securities Corp.		2.21			10/31/18		11/01/18		5,000		5,000	5,000,307	U.S. Treasury Obligations, 0.00% to 5.50%, due 2/28/20 to 10/20/48	73,785,384	5,190,367
Total BNP Paribas Securities Corp.										$	20,000				$20,490,426
HSBC Securities (USA), Inc.		2.21			10/31/18		11/01/18		5,000		5,000	5,000,307	U.S. Government Sponsored Agency Obligations, 4.50%, due 1/20/47	8,971,867	5,100,001
HSBC Securities (USA), Inc.		2.19			10/31/18		11/01/18		10,000		10,000	10,000,608	U.S. Treasury Obligations, 0.00% to 2.75%, due 11/08/18 to 8/15/47	11,461,000	10,200,003
Total HSBC Securities (USA), Inc.										$	15,000				$15,300,004
J.P. Morgan Securities LLC		2.19			10/31/18		11/01/18		15,000		15,000	15,000,913	U.S. Treasury Obligations, 2.88%, due 5/31/25	15,281,100	15,300,009
Merrill Lynch, Pierce, Fenner & Smith, Inc.		2.20			10/31/18		11/01/18		10,000		10,000	10,000,611	U.S. Treasury Obligations, 4.38%, due 11/15/39	8,614,900	10,200,022
Merrill Lynch, Pierce, Fenner & Smith, Inc.		2.22			10/31/18		11/01/18		10,000		10,000	10,000,617	U.S. Government Sponsored Agency Obligations, 4.00%, due 8/15/47	10,180,903	10,200,000
Total Merrill Lynch, Pierce, Fenner & Smith, Inc.										$	20,000				$20,400,022
Mizuho Securities USA, Inc.		2.21			10/31/18		11/01/18		1,000		1,000	1,000,061	U.S. Treasury Obligations, 2.63%, due 7/15/21	1,019,200	1,020,045
Mufg Securities Americas Inc.		2.20			10/31/18		11/01/18		5,000		5,000	5,000,306	U.S. Government Sponsored Agency Obligations, 3.00% to 4.50%, due 4/01/47 to 1/01/48	5,636,741	5,150,000
TD Securities (USA) LLC		2.19			10/31/18		11/01/18		5,000		5,000	5,000,304	U.S. Treasury Obligations, 2.25%, due 1/31/24	5,251,000	5,100,034
TD Securities (USA) LLC		2.21			10/31/18		11/01/18		1,000		1,000	1,000,061	U.S. Treasury Obligations, 2.25%, due 1/31/24	1,050,200	1,020,007
Total TD Securities (USA) LLC										$	6,000				$6,120,041
										$	82,000				$83,780,547

SCHEDULES OF INVESTMENTS 25

Schedule of Investments  (unaudited) (continued) October 31, 2018 Master Premier Government Institutional Portfolio

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of investments. For information about the Master Portfolio’s policy regarding valuation of investments, refer to the Notes to Financial Statements.

The following table summarizes the Master Portfolio’s investments categorized in the disclosure hierarchy:

	Level 1			Level 2		Level 3		Total
Assets:
Investments:
Short-Term Securities(a)	$	—	��	$	116,951,711	$	—	$	116,951,711

^(a)  See above Schedule of Investments for values in each security type.

During the period ended October 31, 2018, there were no transfers between levels.

See notes to financial statements.

26 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Schedule of Investments  (unaudited) October 31, 2018 Master Treasury Strategies Institutional Portfolio (Percentages shown are based on Net Assets)

Security	Par (000)		Value
U.S. Treasury Obligations — 99.9%
U.S. Treasury Bills(a):
2.13%, 11/08/18	$	169,000	$	168,931,156
2.19%, 11/15/18		143,200		143,079,991
2.13%, 11/23/18		67,410		67,323,900
U.S. Treasury Notes:
1.50%, 01/31/19		11,715		11,694,655
1.38%, 02/28/19		2,940		2,931,658
(3 mo. Treasury money market yield + 0.06%), 2.37%, 07/31/19(b)		4,800		4,803,741
Total Investments — 99.9% (Cost — $398,765,101*)				398,765,101
Other Assets Less Liabilities — 0.1%				533,677
Net Assets — 100.0%			$	399,298,778

* Cost for U.S. federal income tax purposes.

^(a)  Rates are discount rates or a range of discount rates as of period end.

^(b)  Variable rate security. Rate shown is the rate in effect as of period end.

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of investments. For information about the Master Portfolio’s policy regarding valuation of investments, refer to the Notes to Financial Statements.

The following table summarizes the Master Portfolio’s investments categorized in the disclosure hierarchy:

	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Short-Term Securities(a)	$	—	$	398,765,101	$	—	$	398,765,101

^(a)  See above Schedule of Investments for values in each Security type.

During the period ended October 31, 2018, there were no transfers between levels.

See notes to financial statements.

SCHEDULES OF INVESTMENTS 27

Statements of Assets and Liabilities  (unaudited)

October 31, 2018

	Master Premier Government Institutional Portfolio		Master Treasury Strategies Institutional Portfolio
ASSETS
Investments at value — unaffiliated(a)	$	34,951,711	$	398,765,101
Repurchase agreements at value — unaffiliated(b)		82,000,000		—
Cash		10,175,830		577,872
Interest receivable — unaffiliated		5,008		51,650
Prepaid expenses		50		—
Total assets		127,132,599		399,394,623
LIABILITIES
Payables:
Custodian fees		39,541		42,251
Professional fees		34,354		31,621
Investment advisory fees		6,797		17,814
Directors’ fees		2,697		2,597
Other accrued expenses		3,917		1,562
Total liabilities		87,306		95,845
NET ASSETS	$	127,045,293	$	399,298,778
NET ASSETS CONSIST OF
Investors’ capital	$	127,045,293	$	399,298,778
NET ASSETS	$	127,045,293	$	399,298,778
(a) Investments at cost — unaffiliated	$	34,951,711	$	398,765,101
(b) Repurchase agreements at cost — unaffiliated	$	82,000,000	$	—

See notes to financial statements.

28 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Statements of Operations  (unaudited)

Six Months Ended October 31, 2018

	Master Premier Government Institutional Portfolio		Master Treasury Strategies Institutional Portfolio
INVESTMENT INCOME
Interest — unaffiliated	$	2,058,338	$	4,282,356
EXPENSES
Investment advisory		57,765		114,376
Rating Agency		—		26,743
Accounting services		9,174		18,548
Custodian		4,305		9,957
Insurance		2,446		2,797
Printing		14		—
Professional		33,361		14,670
Directors		5,867		6,420
Miscellaneous		249		108
Total expenses		113,181		193,619
Less fees waived and/or reimbursed by the Manager		—		(2,356	)
Total expenses after fees waived and/or reimbursed		113,181		191,263
Net investment income		1,945,157		4,091,093
REALIZED GAIN
Net realized gain from investments — unaffiliated		—		770
NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS	$	1,945,157	$	4,091,863

See notes to financial statements.

FINANCIAL STATEMENTS 29

Statements of Changes in Net Assets

	Master Premier Government Institutional Portfolio						Master Treasury Strategies Institutional Portfolio
	Six Months Ended 10/31/18 (unaudited)			Year Ended 04/30/18			Six Months Ended 10/31/18 (unaudited)			Year Ended 04/30/18
INCREASE (DECREASE) IN NET ASSETS
OPERATIONS
Net investment income	$	1,945,157		$	15,707,879		$	4,091,093		$	11,269,241
Net realized gain		—			68,084			770			155,491
Net increase in net assets resulting from operations		1,945,157			15,775,963			4,091,863			11,424,732
CAPITAL TRANSACTIONS
Proceeds from contributions		2,018,221			6,976,550,442			2,563,284			1,445,933,002
Value of withdrawals		(216,522,974	)		(9,211,600,959	)		(115,571,622	)		(2,258,445,308	)
Net decrease in net assets derived from capital share transactions		(214,504,753	)		(2,235,050,517	)		(113,008,338	)		(812,512,306	)
NET ASSETS
Total decrease in net assets		(212,559,596	)		(2,219,274,554	)		(108,916,475	)		(801,087,574	)
Beginning of period		339,604,889			2,558,879,443			508,215,253			1,309,302,827
End of period	$	127,045,293		$	339,604,889		$	399,298,778		$	508,215,253

See notes to financial statements.

30 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Financial Highlights

	Master Premier Government Institutional Portfolio
	Six Months Ended 10/31/18 (unaudited)			Year Ended April 30,
				2018			2017			2016			2015			2014
Total Return
Total return		0.98	%(a)		1.04	%		0.42	%		0.24	%		0.19	%		0.19	%
Ratios to Average Net Assets
Total expenses		0.10	%(b)		0.07	%		0.06	%		0.06	%		0.06	%		0.06	%
Total expenses after fees paid indirectly		0.10	%(b)		0.07	%		0.06	%		0.06	%		0.06	%		0.06	%
Net investment income		1.68	%(b)		0.92	%		0.39	%		0.24	%		0.18	%		0.18	%
Supplemental Data
Net assets, end of period (000)	$	127,045		$	339,605		$	2,558,879		$	3,170,602		$	3,441,445		$	6,614,333

^(a)  Aggregate total return.

^(b)  Annualized.

See notes to financial statements.

FINANCIAL HIGHLIGHTS 31

Financial Highlights  (continued)

	Master Treasury Strategies Institutional Portfolio
	Six Months Ended 10/31/18 (unaudited)			Year Ended April 30,
				2018			2017			2016			2015			2014
Total Return
Total return		0.91	%(a)		1.07	%		0.39	%		0.22	%		0.18	%		0.17	%
Ratios to Average Net Assets
Total expenses		0.08	%(b)		0.07	%		0.07	%		0.06	%		0.06	%		0.06	%
Total expenses after fees waived and/or reimbursed and paid indirectly		0.08	%(b)		0.07	%		0.07	%		0.06	%		0.06	%		0.06	%
Net investment income		1.79	%(b)		1.00	%		0.36	%		0.22	%		0.16	%		0.16	%
Supplemental Data
Net assets, end of period (000)	$	399,299		$	508,215		$	1,309,303		$	2,379,151		$	3,474,716		$	4,525,195

^(a)  Aggregate total return.

^(b)  Annualized.

See notes to financial statements.

32 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Notes to Financial Statements  (unaudited) Master Institutional Money Market LLC

1. ORGANIZATION

Master Institutional Money Market LLC (the “Master LLC”) is registered under the Investment Company Act of 1940, as amended (the “1940 Act”), as an open-end management investment company. The Master LLC is classified as diversified. The Master LLC is organized as a Delaware limited liability company. The Master LLC’s Limited Liability Company Agreement permits the Board of Directors of the Master LLC (the “Board”) to issue non-transferable interests, subject to certain limitations. The financial statements relate to two series of the Master LLC: Master Premier Government Institutional Portfolio and Master Treasury Strategies Institutional Portfolio (each, a “Master Portfolio” and together, the “Master Portfolios”).

Each Master Portfolio operates as a “government money market fund” under Rule 2a-7 under the 1940 Act. Each Master Portfolio is not subject to liquidity fees or temporary suspensions of redemptions due to declines in a Master Portfolio’s weekly liquid assets.

The Master LLC, together with certain other registered investment companies advised by BlackRock Advisors, LLC (the “Manager”) or its affiliates, is included in a complex of open-end funds referred to as the Equity-Liquidity Complex.

2. SIGNIFICANT ACCOUNTING POLICIES

The financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”), which may require management to make estimates and assumptions that affect the reported amounts of assets and liabilities in the financial statements, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of increases and decreases in net assets from operations during the reporting period. Actual results could differ from those estimates. Each Master Portfolio is considered an investment company under U.S. GAAP and follows the accounting and reporting guidance applicable to investment companies. Below is a summary of significant accounting policies:

Investment Transactions and Income Recognition: For financial reporting purposes, investment transactions are recorded on the dates the transactions are entered into (the “trade dates”). Realized gains and losses on investment transactions are determined on the identified cost basis. Interest income, including amortization and accretion of premiums and discounts on debt securities, is recognized on an accrual basis.

Recent Accounting Standards: In March 2017, the Financial Accounting Standards Board issued Accounting Standards Update “Premium Amortization of Purchased Callable Debt Securities” which amends the amortization period for certain purchased callable debt securities. Under the new guidance, the premium amortization of purchased callable debt securities that have explicit, non-contingent call features and are callable at fixed prices will be amortized to the earliest call date. The guidance will be applied on a modified retrospective basis and is effective for fiscal years, and their interim periods, beginning after December 15, 2018. Management is currently evaluating the impact of this guidance to the Master Portfolios.

In August 2018, the Financial Accounting Standards Board issued Accounting Standards Update 2018-13 “Changes to the Disclosure Requirements for Fair Value Measurement” which modifies disclosure requirements for fair value measurements. The guidance is effective for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. Management is currently evaluating the impact of this guidance to the Master Portfolios.

Indemnifications: In the normal course of business, a Master Portfolio enters into contracts that contain a variety of representations that provide general indemnification. A Master Portfolio’s maximum exposure under these arrangements is unknown because it involves future potential claims against a Master Portfolio, which cannot be predicted with any certainty.

Other: Expenses directly related to a Master Portfolio are charged to that Master Portfolio. Other operating expenses shared by several funds, including other funds managed by the Manager, are prorated among those funds on the basis of relative net assets or other appropriate methods.

3. INVESTMENT VALUATION AND FAIR VALUE MEASUREMENTS

Investment Valuation Policies: U.S. GAAP defines fair value as the price the Master Portfolios would receive to sell an asset or pay to transfer a liability in an orderly transaction between market participants at the measurement date. The Master Portfolios’ investments are valued under the amortized cost method which approximates current market value in accordance with Rule 2a-7 under the 1940 Act. Under this method, investments are valued at cost when purchased and, thereafter, a constant proportionate accretion of discounts and amortization of premiums are recorded until the maturity of the security. Each Master Portfolio seeks to maintain the net asset value (“NAV”) per share of its feeder funds at $1.00, although there is no assurance that it will be able to do so on a continuing basis.

Fair Value Hierarchy: Various inputs are used in determining the fair value of investments. These inputs to valuation techniques are categorized into a fair value hierarchy consisting of three broad levels for financial statement purposes as follows:

• Level 1 — Unadjusted price quotations in active markets/exchanges for identical assets or liabilities that each Master Portfolio has the ability to access

• Level 2 — Other observable inputs (including, but not limited to, quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market–corroborated inputs)

• Level 3 — Unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including each Master Portfolio’s own assumptions used in determining the fair value of investments)

The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Accordingly, the degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3.

NOTESTO FINANCIAL STATEMENTS 33

Notes to Financial Statements  (unaudited) (continued) Master Institutional Money Market LLC

The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the fair value hierarchy classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety.

Changes in valuation techniques may result in transfers into or out of an assigned level within the hierarchy. In accordance with each Master Portfolio’s policy, transfers between different levels of the fair value hierarchy are deemed to have occurred as of the beginning of the reporting period. The categorization of a value determined for investments is based on the pricing transparency of the investments and is not necessarily an indication of the risks associated with investing in those securities.

4. SECURITIES AND OTHER INVESTMENTS

Repurchase Agreements: Repurchase agreements are commitments to purchase a security from a counterparty who agrees to repurchase the same security at a mutually agreed upon date and price. On a daily basis, the counterparty is required to maintain collateral subject to the agreement and in value no less than the agreed upon repurchase amount. Pursuant to the custodial undertaking associated with a tri-party repurchase arrangement, an unaffiliated third party custodian maintains accounts to hold collateral for a Master Portfolio and its counterparties. Typically, a Master Portfolio and counterparty are not permitted to sell, re-pledge or use the collateral absent a default by the counterparty or a Master Portfolio, respectively. A Master Portfolio, along with other registered investment companies advised by the Manager, may transfer uninvested cash into a single joint trading account which is then invested in one or more repurchase agreements. As of period end, there were no joint trading accounts invested in repurchase agreements.

In the event the counterparty defaults and the fair value of the collateral declines, a Master Portfolio could experience losses, delays and costs in liquidating the collateral.

Repurchase agreements are entered into by a Master Portfolio under Master Repurchase Agreements (each, an “MRA”). The MRA permits a Master Portfolio, under certain circumstances including an event of default (such as bankruptcy or insolvency), to offset payables and/or receivables with collateral held by and/or posted to the counterparty. As a result, one single net payment is created. Bankruptcy or insolvency laws of a particular jurisdiction may impose restrictions on or prohibitions against such a right of offset in the event of the MRA counterparty’s bankruptcy or insolvency. Based on the terms of the MRA, a Master Portfolio receives securities as collateral with a market value in excess of the repurchase price at maturity. Upon a bankruptcy or insolvency of the MRA counterparty, a Master Portfolio would recognize a liability with respect to such excess collateral. The liability reflects a Master Portfolio’s obligation under bankruptcy law to return the excess to the counterparty.

5. INVESTMENT ADVISORY/ADMINISTRATION AGREEMENT AND OTHER TRANSACTIONS WITH AFFILIATES

The PNC Financial Services Group, Inc. is the largest stockholder and an affiliate of BlackRock, Inc. (“BlackRock”) for 1940 Act purposes.

Investment Advisory: The Master LLC, on behalf of the Master Portfolios, entered into an Investment Advisory Agreement with the Manager, the Master Portfolios’ investment adviser and an indirect, wholly-owned subsidiary of BlackRock, to provide investment advisory and administrative services. The Manager is responsible for the management of each Master Portfolio’s portfolio and provides the personnel, facilities, equipment and certain other services necessary to the operations of each Master Portfolio.

For such services, each Master Portfolio pays the Manager a monthly fee at an annual rate equal to 0.05% of the average daily value of each Master Portfolio’s net assets.

Expense Waivers: The Manager voluntarily agreed to waive a portion of its respective management fees and/or reimburse operating expenses to enable the Master Portfolios to maintain minimum levels of daily net investment income. These amounts, if any, are reported in the Statements of Operations as fees waived and/or reimbursed by the Manager. The Manager may discontinue the waiver and/or reimbursement at any time.

Directors and Officers: Certain directors and/or officers of the Master LLC are directors and/or officers of BlackRock or its affiliates.

6. INCOME TAX INFORMATION

Each Master Portfolio is classified as a partnership for U.S. federal income tax purposes. As such, each investor in the Master Portfolios is treated as the owner of its proportionate share of net assets, income, expenses and realized and unrealized gains and losses of the Master Portfolios. Therefore, no U.S. federal income tax provision is required.

Each Master Portfolio files U.S. federal and various state and local tax returns. No income tax returns are currently under examination. The statute of limitations on each Master Portfolio’s U.S. federal tax returns generally remains open for each of the four years ended April 30, 2018. The statutes of limitations on each Master Portfolio’s state and local tax returns may remain open for an additional year depending upon the jurisdiction.

Management has analyzed tax laws and regulations and their application to the Master Portfolios as of October 31, 2018, inclusive of the open tax return years, and does not believe that there are any uncertain tax positions that require recognition of a tax liability in the Master Portfolios’ financial statements.

7. PRINCIPAL RISKS

In the normal course of business, the Master Portfolios invest in securities or other instruments and may enter into certain transactions, and such activities subject each Master Portfolio to various risks, including among others, fluctuations in the market (market risk) or failure of an issuer to meet all of its obligations. The value of securities or other instruments may also be affected by various factors, including, without limitation: (i) the general economy; (ii) the overall market as well as local, regional or global political and/or social instability; (iii) regulation, taxation or international tax treaties between various countries; or (iv) currency, interest rate and price fluctuations. Each Master Portfolio’s prospectus provides details of the risks to which each Master Portfolio is subject.

34 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Notes to Financial Statements  (unaudited) (continued) Master Institutional Money Market LLC

Counterparty Credit Risk: The Master Portfolios may be exposed to counterparty credit risk, or the risk that an entity may fail to or be unable to perform on its commitments related to unsettled or open transactions. The Master Portfolios manage counterparty credit risk by entering into transactions only with counterparties that the Manager believes have the financial resources to honor their obligations and by monitoring the financial stability of those counterparties. Financial assets, which potentially expose the Master Portfolios to market, issuer and counterparty credit risks, consist principally of financial instruments and receivables due from counterparties. The extent of the Master Portfolios’ exposure to market, issuer and counterparty credit risks with respect to these financial assets is approximately their value recorded in the Statements of Assets and Liabilities, less any collateral held by the Master Portfolios.

8. SUBSEQUENT EVENTS

Management has evaluated the impact of all subsequent events on the Master Portfolios through the date the financial statements were issued and has determined that there were no subsequent events requiring adjustment or additional disclosure in the financial statements.

NOTESTO FINANCIAL STATEMENTS 35

Disclosure of Investment Advisory Agreements

The Board of Directors of Master Institutional Money Market LLC (the “Master LLC”) met in person on April 19, 2018 (the “April Meeting”) and May 17-18, 2018 (the “May Meeting”) to consider the approval of the investment advisory agreement (the “Master LLC Agreement”) between the Master LLC, on behalf of Master Premier Government Institutional Portfolio and Master Treasury Strategies Institutional Portfolio (each a “Master Portfolio,” and together, the “Master Portfolios”), each a series of the Master LLC, and BlackRock Advisors, LLC (the “Manager” or “BlackRock”), the Master LLC’s investment advisor.

BlackRock Premier Government Institutional Fund (“Premier Government Institutional Fund”), BlackRock Select Treasury Strategies Institutional Fund (“Select Treasury Strategies Institutional Fund”) and BlackRock Treasury Strategies Institutional Fund (“Treasury Strategies Institutional Fund”) (each a “Feeder Fund,” and together, the “Feeder Funds”), three of the series comprising Funds For Institutions Series (the “Series Fund”), currently invest all of their respective investable assets in Master Portfolios of the Master LLC as follows: Select Treasury Strategies Institutional Fund and Treasury Strategies Institutional Fund in Master Treasury Strategies Institutional Portfolio and Premier Government Institutional Fund in Master Premier Government Institutional Portfolio. Accordingly, the Board of Trustees of the Series Fund also considered the approval of the Master LLC Agreement. The Board of Trustees of the Series Fund also considered the approval of the investment advisory agreement (the “Government Fund Agreement”) between BlackRock and the Series Fund on behalf of FFI Government Fund, a series of the Series Fund, and the investment advisory agreement (the “Treasury Fund Agreement”) between BlackRock and the Series Fund on behalf of FFI Treasury Fund, also a series of the Series Fund.

The Master LLC Agreement, the Government Fund Agreement and the Treasury Fund Agreement are referred to herein as the “Agreements.” For simplicity: (a) the Board of Directors of the Master LLC and the Board of Trustees of the Series Fund are referred to herein collectively as the “Board,” and the members are referred to as “Board Members”; (b) the Feeder Funds, the corresponding Master Portfolios, FFI Government Fund and FFI Treasury Fund are sometimes referred to herein individually as a “Fund” and collectively as the “Funds”; and (c) the shareholders of the Feeder Funds, FFI Government Fund and FFI Treasury Fund and the interest holders of the Master Portfolios are referred to as “shareholders.”

Activities and Composition of the Board

On the date of the May Meeting, the Board consisted of thirteen individuals, eleven of whom were not “interested persons” of the Master LLC or the Series Fund as defined in the Investment Company Act of 1940, as amended (the “1940 Act”) (the “Independent Board Members”). The Board Members are responsible for the oversight of the operations of the Master LLC, the Series Fund or each Fund, as pertinent, and perform the various duties imposed on the directors of investment companies by the 1940 Act. The Independent Board Members have retained independent legal counsel to assist them in connection with their duties. The Chair of the Board is an Independent Board Member. The Board has established five standing committees: an Audit Committee, a Governance and Nominating Committee, a Compliance Committee, a Performance Oversight and Contract Committee and an Executive Committee, each of which is chaired by an Independent Board Member and composed of Independent Board Members (except for the Executive Committee, which also has one interested Board Member).

The Agreements

Pursuant to the 1940 Act, the Board is required to consider the continuation of the Agreements on an annual basis. The Board has four quarterly meetings per year, each typically extending for two days, and additional in-person and telephonic meetings throughout the year, as needed. The Board also has a fifth one-day meeting to consider specific information surrounding the consideration of renewing the Agreements. The Board’s consideration of the Agreements is a year-long deliberative process, during which the Board assessed, among other things, the nature, extent and quality of the services provided to the Funds by BlackRock, BlackRock’s personnel and affiliates, including (as applicable): investment management; accounting, administrative and shareholder services; oversight of the Funds’ service providers; marketing and promotional services; risk management and oversight; legal and compliance services; and ability to meet applicable legal and regulatory requirements.

The Board, acting directly and through its committees, considers at each of its meetings, and from time to time as appropriate, factors that are relevant to its annual consideration of the renewal of the Agreements, including the services and support provided by BlackRock to the Funds and their shareholders. BlackRock also furnished additional information to the Board in response to specific questions from the Board. This additional information is discussed further below in the section titled “Board Considerations in Approving the Agreements.” Among the matters the Board considered, with respect to each Fund, as pertinent, were: (a) investment performance for one-year, three-year, five-year, ten-year, and/or since inception periods, as applicable, against peer funds, applicable benchmark, and performance metrics, as applicable, as well as senior management’s and portfolio managers’ analysis of the reasons for any over-performance or underperformance relative to its peers, benchmarks, and other performance metrics, as applicable; (b) fees, including advisory, administration, if applicable, and other amounts paid to BlackRock and its affiliates by the Fund for services; (c) Fund operating expenses and how BlackRock allocates expenses to the Fund; (d) the resources devoted to, risk oversight of, and compliance reports relating to, implementation of the Fund’s investment objective(s), policies and restrictions, and meeting regulatory requirements; (e) the Master LLC’s and the Series Fund’s adherence to its respective compliance policies and procedures; (f) the nature, character and scope of non-investment management services provided by BlackRock and its affiliates and the estimated cost of such services; (g) BlackRock’s and other service providers’ internal controls and risk and compliance oversight mechanisms; (h) BlackRock’s implementation of the proxy voting policies approved by the Board; (i) execution quality of portfolio transactions; (j) BlackRock’s implementation of the Master LLC’s and/or the Series Fund’s valuation and liquidity procedures; (k) an analysis of management fees for products with similar investment mandates across the open-end fund, exchange-traded fund (“ETF”), closed-end fund, sub-advised mutual fund, separately managed account, collective investment trust, and institutional separate account product channels, as applicable, and the similarities and differences between these products and the services provided as compared to the Fund; (l) BlackRock’s compensation methodology for its investment professionals and the incentives and accountability it creates, along with investment professionals’ investments in the fund(s) they manage; and (m) periodic updates on BlackRock’s business.

Board Considerations in Approving the Agreements

The Approval Process: Prior to the April Meeting, the Board requested and received materials specifically relating to the Agreements. The Board is continuously engaged in a process with its independent legal counsel and BlackRock to review the nature and scope of the information provided to better assist its deliberations. The materials provided in connection with the April Meeting included, among other things: (a) information independently compiled and prepared by Broadridge Financial Solutions, Inc. (“Broadridge”), based on either a Lipper classification or Morningstar category, regarding the fees and expenses of each applicable Fund as compared with a peer group of

36 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Disclosure of Investment Advisory Agreements  (continued)

funds as determined by Broadridge (“Expense Peers”) and the investment performance of each Feeder Fund, FFI Government Fund and FFI Treasury Fund as compared with a peer group of funds (“Performance Peers”) and other metrics, as applicable; (b) information on the composition of the Expense Peers and Performance Peers, and a description of Broadridge’s methodology; (c) information on the estimated profits realized by BlackRock and its affiliates pursuant to the Agreements and a discussion of fall-out benefits to BlackRock and its affiliates; (d) a general analysis provided by BlackRock concerning investment management fees received in connection with other types of investment products, such as institutional accounts, sub-advised mutual funds, ETFs, closed-end funds, open-end funds, and separately managed accounts under similar investment mandates, as well as the performance of such other products, as applicable; (e) review of non-management fees; (f) the existence and impact of potential economies of scale, if any, and the sharing of potential economies of scale with the Funds; (g) a summary of aggregate amounts paid by each applicable Fund to BlackRock; (h) sales and redemption data regarding the shares of each Feeder Fund, FFI Government Fund and FFI Treasury Fund; and (i) various additional information requested by the Board as appropriate regarding BlackRock’s and the Funds’ operations.

At the April Meeting, the Board reviewed materials relating to its consideration of the Agreements. As a result of the discussions that occurred during the April Meeting, and as a culmination of the Board’s year-long deliberative process, the Board presented BlackRock with questions and requests for additional information. BlackRock responded to these requests with additional written information in advance of the May Meeting.

At the May Meeting, the Board considered, with respect to the pertinent Fund, among other things: (a) the nature, extent and quality of the services provided by BlackRock; (b) the investment performance of the Fund as compared with its Performance Peers and other metrics, as applicable; (c) the advisory fee and the estimated cost of the services and estimated profits realized by BlackRock and its affiliates from their relationship with the Fund; (d) the Fund’s fees and expenses compared to its Expense Peers; (e) the sharing of potential economies of scale; (f) fall-out benefits to BlackRock and its affiliates as a result of BlackRock’s relationship with the Fund; and (g) other factors deemed relevant by the Board Members.

The Board also considered other matters it deemed important to the approval process, such as other payments made to BlackRock or its affiliates, securities lending and cash management, services related to the valuation and pricing of the portfolio holdings of the applicable Fund, and advice from independent legal counsel with respect to the review process and materials submitted for the Board’s review. The Board noted the willingness of BlackRock personnel to engage in open, candid discussions with the Board. The Board did not identify any particular information as determinative, and each Board Member may have attributed different weights to the various items considered.

A. Nature, Extent and Quality of the Services Provided by BlackRock: The Board, including the Independent Board Members, reviewed the nature, extent and quality of services provided by BlackRock, including the investment advisory services and the resulting performance of each Feeder Fund, FFI Government Fund and FFI Treasury Fund. Throughout the year, the Board compared the applicable Fund’s performance to the performance of a comparable group of mutual funds, relevant benchmark, and performance metrics, as applicable. The Board met with BlackRock’s senior management personnel responsible for investment activities, including the senior investment officers. The Board also reviewed the materials provided by the applicable Fund’s portfolio management team discussing the Fund’s performance and the Fund’s investment objective(s), strategies and outlook.

The Board considered, among other factors, with respect to BlackRock: the number, education and experience of investment personnel generally and the applicable Fund’s portfolio management team; BlackRock’s research capabilities; investments by portfolio managers in the funds they manage; portfolio trading capabilities; use of technology; commitment to compliance; credit analysis capabilities; risk analysis and oversight capabilities; and the approach to training and retaining portfolio managers and other research, advisory and management personnel. The Board also considered BlackRock’s overall risk management program, including the continued efforts of BlackRock and its affiliates to address cybersecurity risks and the role of BlackRock’s Risk & Quantitative Analysis Group. The Board engaged in a review of BlackRock’s compensation structure with respect to the applicable Fund’s portfolio management team and BlackRock’s ability to attract and retain high-quality talent and create performance incentives.

In addition to investment advisory services, the Board considered the quality of the administrative and other non-investment advisory services provided to the Funds. BlackRock and its affiliates provide the Funds with certain administrative, shareholder and other services (in addition to any such services provided to the Funds by third parties) and officers and other personnel as are necessary for the operations of the Funds. In particular, BlackRock and its affiliates provide each Fund with administrative services including, among others: (i) responsibility for disclosure documents, such as the prospectus, the summary prospectus (as applicable), the statement of additional information and periodic shareholder reports; (ii) oversight of daily accounting and pricing; (iii) responsibility for periodic filings with regulators; (iv) overseeing and coordinating the activities of other service providers, including, among others, the Fund’s custodian, fund accountant, transfer agent, and auditor; (v) organizing Board meetings and preparing the materials for such Board meetings; (vi) providing legal and compliance support; (vii) furnishing analytical and other support to assist the Board in its consideration of strategic issues such as the merger, consolidation or repurposing of certain open-end funds; and (viii) performing administrative functions necessary for the operation of each Fund, such as tax reporting, expense management, fulfilling regulatory filing requirements, overseeing the Fund’s distribution partners, and shareholder call center and other services. The Board reviewed the structure and duties of BlackRock’s fund administration, shareholder services, and legal & compliance departments and considered BlackRock’s policies and procedures for assuring compliance with applicable laws and regulations.

B. The Investment Performance of the Funds and BlackRock: The Board, including the Independent Board Members, also reviewed and considered the performance history of each Feeder Fund, each Master Portfolio, FFI Government Fund and FFI Treasury Fund, as applicable. The Board noted that each Feeder Fund’s investment results correspond directly to the investment results of the applicable Master Portfolio. In preparation for the April Meeting, the Board was provided with reports independently prepared by Broadridge, which included a comprehensive analysis of the performance of each Feeder Fund, FFI Government Fund and FFI Treasury Fund as of December 31, 2017. Broadridge ranks funds in quartiles, ranging from first to fourth, where first is the most desirable quartile position and fourth is the least desirable. In connection with its review, the Board received and reviewed information regarding the investment performance of each Feeder Fund, FFI Government Fund and FFI Treasury Fund as compared to the applicable Fund’s Performance Peers. The Board and its Performance Oversight and Contract Committee regularly review, and meet with Fund management to discuss, the performance of each Fund throughout the year.

DISCLOSUREOF INVESTMENT ADVISORY AGREEMENTS 37

Disclosure of Investment Advisory Agreements  (continued)

In evaluating performance, the Board recognized that the performance data reflects a snapshot of a period as of a particular date and that selecting a different performance period could produce significantly different results. Further, the Board recognized that it is possible that long-term performance can be impacted by even one period of significant outperformance or underperformance, so that a single investment theme has the ability to affect long-term performance disproportionately.

The Board reviewed each Fund’s performance within the context of the low yield environment that has existed over the past several years.

The Board noted that for the one-, three- and five-year periods reported, Premier Government Institutional Fund and Select Treasury Strategies Institutional Fund each ranked in the second, first and first quartiles, respectively, against its Performance Peers.

The Board noted that for the one-, three- and five-year periods reported, Treasury Strategies Institutional Fund ranked in the third, second and second quartiles, respectively, against its Performance Peers.

The Board noted that for the one-, three- and five-year periods reported, FFI Treasury Fund ranked in the third, third and second quartiles, respectively, against its Performance Peers.

The Board noted that for each of the one-, three- and five-year periods reported, FFI Government Fund ranked in the third quartile against its Performance Peers.

The quartile standing of each Fund against its Performance Peers takes into account the Fund’s current yield only. BlackRock has reviewed with the Board that a money market fund can only be understood holistically, accounting for current yield and risk. While the Board reviews each Fund’s current yield performance, it also examines the liquidity, duration, and credit quality of the Fund’s portfolio. In the Board’s view, BlackRock’s money market funds have performed well over the one-, three- and five-year periods given BlackRock’s emphasis on preserving capital and seeking as high a level of current income as is consistent with liquidity while simultaneously managing risk.

C. Consideration of the Advisory/Management Fees and the Estimated Cost of the Services and Estimated Profits Realized by BlackRock and its Affiliates from their Relationship with the Funds: The Board, including the Independent Board Members, reviewed the contractual management fee rate of each Master Portfolio/Feeder Fund, FFI Government Fund and FFI Treasury Fund compared with those of the corresponding Expense Peers. The contractual management fee rate represents a combination of the advisory fee and any administrative fees, before taking into account any reimbursements or fee waivers. The Board also compared the total expense ratio, as well as the actual management fee rate of each Master Portfolio/Feeder Fund, FFI Government Fund and FFI Treasury Fund, to those of the corresponding Expense Peers. The total expense ratio represents a fund’s total net operating expenses, including any 12b-1 or non 12b-1 service fees. The total expense ratio gives effect to any expense reimbursements or fee waivers that benefit a fund, and the actual management fee rate gives effect to any management fee reimbursements or waivers that benefit a fund. The Board considered the services provided and the fees charged by BlackRock and its affiliates to other types of clients with similar investment mandates, as applicable, including institutional accounts and sub-advised mutual funds (including mutual funds sponsored by third parties).

The Board received and reviewed statements relating to BlackRock’s financial condition. The Board reviewed BlackRock’s profitability methodology and was also provided with an estimated profitability analysis that detailed the revenues earned and the expenses incurred by BlackRock for services provided to the Funds. The Board reviewed BlackRock’s estimated profitability with respect to the Funds and other funds the Board currently oversees for the year ended December 31, 2017 compared to available aggregate estimated profitability data provided for the prior two years. The Board reviewed BlackRock’s estimated profitability with respect to certain other U.S. fund complexes managed by the Manager and/or its affiliates. The Board reviewed BlackRock’s assumptions and methodology of allocating expenses in the estimated profitability analysis, noting the inherent limitations in allocating costs among various advisory products. The Board recognized that profitability may be affected by numerous factors including, among other things, fee waivers and expense reimbursements by the Manager, the types of funds managed, precision of expense allocations and business mix. As a result, calculating and comparing profitability at individual fund levels is difficult.

The Board noted that, in general, individual fund or product line profitability of other advisors is not publicly available. The Board reviewed BlackRock’s overall operating margin, in general, compared to that of certain other publicly-traded asset management firms. The Board considered the differences between BlackRock and these other firms, including the contribution of technology at BlackRock, BlackRock’s expense management, and the relative product mix.

In addition, the Board considered the estimated cost of the services provided to each Fund by BlackRock, and BlackRock’s and its affiliates’ estimated profits relating to the management and distribution of the applicable Fund and the other funds advised by BlackRock and its affiliates. As part of its analysis, the Board reviewed BlackRock’s methodology in allocating its costs of managing the applicable Fund, to the Fund. The Board considered whether BlackRock has the financial resources necessary to attract and retain high quality investment management personnel to perform its obligations under the Agreements and to continue to provide the high quality of services that is expected by the Board. The Board further considered factors including but not limited to BlackRock’s commitment of time, assumption of risk, and liability profile in servicing the Funds in contrast to what is required of BlackRock with respect to other products with similar investment mandates across the open-end fund, ETF, closed-end fund, sub-advised mutual fund, separately managed account, collective investment trust, and institutional separate account product channels, as applicable.

The Board noted that Master Premier Government Institutional Portfolio’s/Premier Government Institutional Fund’s contractual management fee rate ranked in the first quartile, and that the actual management fee rate and the Fund’s total expense ratio each ranked in the first quartile, relative to the Fund’s Expense Peers. The Board also noted that BlackRock and the Board have contractually agreed to a cap on the Fund’s total expenses as a percentage of the Fund’s average daily net assets.

The Board noted that FFI Government Fund’s contractual management fee rate ranked in the second quartile, and that the actual management fee rate and total expense ratio ranked in the second and first quartiles, respectively, relative to its Expense Peers. The Board further noted that BlackRock and the Board have contractually agreed to waive a portion of the advisory fees for the Fund.

The Board noted that Master Treasury Strategies Institutional Portfolio’s/Select Treasury Strategies Institutional Fund’s contractual management fee rate ranked in the second quartile, and that the actual management fee rate and the Fund’s total expense ratio each ranked in the second quartile, respectively, relative to the Fund’s Expense Peers. The Board also noted that BlackRock and the Board have contractually agreed to a cap on the Fund’s total expenses as a percentage of the Fund’s average daily net assets.

38 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Disclosure of Investment Advisory Agreements  (continued)

The Board noted that Master Treasury Strategies Institutional Portfolio’s/Treasury Strategies Institutional Fund’s contractual management fee rate ranked in the second quartile, and that the actual management fee rate and the Fund’s total expense ratio each ranked in the fourth quartile, relative to the Fund’s Expense Peers.

The Board noted that FFI Treasury Fund’s contractual management fee rate ranked in the fourth quartile, and that the actual management fee rate and total expense ratio each ranked in the fourth quartile, relative to its Expense Peers. The Board additionally noted that BlackRock and the Board have contractually agreed to waive a portion of the advisory fees for the Fund.

The Board noted that FFI Government Fund and FFI Treasury Fund each has an advisory fee arrangement that includes breakpoints that adjust the fee rate downward as the size of the relevant Fund increases above certain contractually specified levels.

The Board reviewed each Fund’s expenses within the context of the low yield environment and consequent expense waivers and reimbursements. The Board also noted that, to enable each Fund to maintain minimum levels of daily net investment income, BlackRock has voluntarily agreed to waive a portion of its fees and/or reimburse each Fund’s operating expenses as necessary.

D. Economies of Scale: The Board, including the Independent Board Members, considered the extent to which economies of scale might be realized as the assets of the applicable Fund increase, including the existence of fee waivers and/or expense caps, as applicable, noting that any contractual fee waivers and expense caps had been approved by the Board. The Board also considered the extent to which the Funds benefit from such economies in a variety of ways and whether there should be changes in the advisory fee rate or breakpoint structure in order to enable the Funds to more fully participate in these economies of scale. The Board considered each Fund’s asset levels and whether the current fee schedule was appropriate. In their consideration, the Board Members took into account the existence of any expense caps and further considered the continuation and/or implementation, as applicable, of such caps.

E. Other Factors Deemed Relevant by the Board Members: The Board, including the Independent Board Members, also took into account other ancillary or “fall-out” benefits that BlackRock or its affiliates may derive from BlackRock’s respective relationships with the applicable Fund, both tangible and intangible, such as BlackRock’s ability to leverage its investment professionals who manage other portfolios and risk management personnel, an increase in BlackRock’s profile in the investment advisory community, and the engagement of BlackRock’s affiliates as service providers to the Fund, including for administrative, distribution, securities lending and cash management services. The Board also considered BlackRock’s overall operations and its efforts to expand the scale of, and improve the quality of, its operations. The Board also noted that, subject to applicable law, BlackRock may use and benefit from third party research obtained by soft dollars generated by certain registered fund transactions to assist in managing all or a number of its other client accounts.

In connection with its consideration of the Agreements, the Board also received information regarding BlackRock’s brokerage and soft dollar practices. The Board received reports from BlackRock which included information on brokerage commissions and trade execution practices throughout the year.

The Board noted the competitive nature of the open-end fund marketplace, and that shareholders are able to redeem their Fund shares if they believe that the pertinent Fund’s fees and expenses are too high or if they are dissatisfied with the performance of the Fund.

Conclusion

The Board of the Master LLC, including the Independent Board Members, approved the continuation of the Master LLC Agreement between BlackRock and the Master LLC with respect to each Master Portfolio for a one-year term ending June 30, 2019. The Board of the Series Fund, including the Independent Board Members, approved the continuation of (i) the Government Fund Agreement between BlackRock and the Series Fund with respect to FFI Government Fund and (ii) the Treasury Fund Agreement between BlackRock and the Series Fund with respect to FFI Treasury Fund, each for a one-year term ending June 30, 2019. Based upon its evaluation of all of the aforementioned factors in their totality, the Board of the Master LLC, including the Independent Board Members, was satisfied that the terms of the Master LLC Agreement were fair and reasonable and in the best interest of each Master Portfolio and its shareholders. Based upon its evaluation of all of the aforementioned factors in their totality, the Board of the Series Fund, including the Independent Board Members, was satisfied that the terms of the Government Fund Agreement and the Treasury Fund Agreement were fair and reasonable and in the best interest of FFI Government Fund and FFI Treasury Fund and their respective shareholders. The Board of the Series Fund, including the Independent Board Members, also considered the continuation of the Master LLC Agreement with respect to each Master Portfolio and found the Master LLC Agreement to be satisfactory

In arriving at their decisions to approve the Agreements, the Boards did not identify any single factor or group of factors as all-important or controlling, but considered all factors together, and different Board Members may have attributed different weights to the various factors considered. The Independent Board Members were also assisted by the advice of independent legal counsel in making this determination.

DISCLOSUREOF INVESTMENT ADVISORY AGREEMENTS 39

Director and Officer Information

Rodney D. Johnson, Chair of the Board and Director

Mark Stalnecker, Chair Elect of the Board and Director

Susan J. Carter, Director

Collette Chilton, Director

Neil A. Cotty, Director

Cynthia A. Montgomery, Director

Joseph P. Platt, Director

Robert C. Robb, Jr., Director

Kenneth L. Urish, Director

Claire A. Walton, Director

Frederick W. Winter, Director

Robert Fairbairn, Director

John M. Perlowski, Director, President and Chief Executive Officer

Thomas Callahan, Vice President

Jennifer McGovern, Vice President

Neal J. Andrews, Chief Financial Officer

Jay M. Fife, Treasurer

Charles Park, Chief Compliance Officer

John MacKessy, Anti-Money Laundering Compliance Officer

Benjamin Archibald, Secretary

At a special meeting of shareholders held on November 21, 2018, each Fund’s interestholders elected Directors to take office on January 1, 2019. The newly-elected Directors include ten current Directors and five individuals who currently serve as directors/trustees of the funds in the BlackRock Equity-Bond Complex. Information regarding the individuals who will serve as Directors effective January 1, 2019 can be found in the proxy statement for the special meeting of shareholders, which is available on the SEC’s EDGAR Database at http://www.sec.gov.

Investment Adviser/Administrator

BlackRock Advisors, LLC

Wilmington, DE 19809

Transfer Agent

DST Asset Manager Solutions, Inc.

Boston, MA 02266

Accounting Agent and Custodian

State Street Bank and Trust Company

Boston, MA 02111

Distributor

BlackRock Investments, LLC

New York, NY 10022

Independent Registered Public Accounting Firm

Deloitte & Touche LLP

Boston, MA 02116

Legal Counsel

Sidley Austin LLP

New York, NY 10019

Address of the Trust/Master LLC

60 State Street

Boston, MA 02109

40 2018 BLACKROCK SEMI-ANNUAL REPORTTO SHAREHOLDERS

Additional Information

General Information

Electronic Delivery

Shareholders can sign up for e-mail notifications of quarterly statements, annual and semi-annual shareholder reports and prospectuses by enrolling in the electronic delivery program. Electronic copies of shareholder reports and prospectuses are available on BlackRock’s website.

To enroll in electronic delivery:

Shareholders Who Hold Accounts with Investment Advisers, Banks or Brokerages:

Please contact your financial adviser. Please note that not all investment advisers, banks or brokerages may offer this service.

Householding

The Funds will mail only one copy of shareholder documents, including prospectuses, annual and semi-annual reports and proxy statements, to shareholders with multiple accounts at the same address. This practice is commonly called “householding” and is intended to reduce expenses and eliminate duplicate mailings of shareholder documents. Mailings of your shareholder documents may be householded indefinitely unless you instruct us otherwise. If you do not want the mailing of these documents to be combined with those for other members of your household, please call the Transfer Agent at (800) 225-1576.

Availability of Quarterly Schedule of Investments

The Trust/Master LLC file their complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-Q. The Trust’s/Master LLC’s Forms N-Q are available on the SEC’s website at http://www.sec.gov. The Trust’s/Master LLC’s Forms N-Q may also be obtained upon request and without charge by calling (800) 626-1960.

Availability of Proxy Voting Policies and Procedures

A description of the policies and procedures that the Trust/Master LLC use to determine how to vote proxies relating to portfolio securities is available upon request and without charge (1) by calling (800) 626-1960; (2) at http://www.blackrock.com; and (3) on the SEC’s website at http://www.sec.gov.

Availability of Proxy Voting Record

Information about how the Trust/Master LLC voted proxies relating to securities held in the Trust’s/Master LLC’s portfolios during the most recent 12-month period ended June 30 is available upon request and without charge (1) at http://www.blackrock.com; or by calling (800) 626-1960 and (2) on the SEC’s website at http://www.sec.gov.

BlackRock Privacy Principles

BlackRock is committed to maintaining the privacy of its current and former fund investors and individual clients (collectively, “Clients”) and to safeguarding their non-public personal information. The following information is provided to help you understand what personal information BlackRock collects, how we protect that information and why in certain cases we share such information with select parties.

If you are located in a jurisdiction where specific laws, rules or regulations require BlackRock to provide you with additional or different privacy-related rights beyond what is set forth below, then BlackRock will comply with those specific laws, rules or regulations.

BlackRock obtains or verifies personal non-public information from and about you from different sources, including the following: (i) information we receive from you or, if applicable, your financial intermediary, on applications, forms or other documents; (ii) information about your transactions with us, our affiliates, or others; (iii) information we receive from a consumer reporting agency; and (iv) from visits to our websites.

BlackRock does not sell or disclose to non-affiliated third parties any non-public personal information about its Clients, except as permitted by law or as is necessary to respond to regulatory requests or to service Client accounts. These non-affiliated third parties are required to protect the confidentiality and security of this information and to use it only for its intended purpose.

We may share information with our affiliates to service your account or to provide you with information about other BlackRock products or services that may be of interest to you. In addition, BlackRock restricts access to non-public personal information about its Clients to those BlackRock employees with a legitimate business need for the information. BlackRock maintains physical, electronic and procedural safeguards that are designed to protect the non-public personal information of its Clients, including procedures relating to the proper storage and disposal of such information.

ADDITIONAL INFORMATION 41

This report is intended for current holders. It is not authorized for use as an offer of sale or a solicitation of an offer to buy shares of a Fund unless preceded or accompanied by the Fund’s current prospectus. You could lose money by investing in a Fund. Although the Funds seek to preserve the value of your investment at $1.00 per share, they cannot guarantee they will do so. An investment in a Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Funds’ sponsor has no legal obligation to provide financial support to the Funds at any time. Performance data quoted represents past performance and does not guarantee future results. Total return information assumes reinvestment of all distributions. Current performance may be higher or lower than the performance data quoted. For current month-end performance information, call (800) 626-1960. Each Fund’s current 7-day yield more closely reflects the current earnings of a Fund than the total returns quoted. Statements and other information herein are as dated and are subject to change.

FFI-10/18-SAR

Item 2 –	Code of Ethics – Not Applicable to this semi-annual report
Item 3 –	Audit Committee Financial Expert – Not Applicable to this semi-annual report
Item 4 –	Principal Accountant Fees and Services – Not Applicable to this semi-annual report
Item 5 –	Audit Committee of Listed Registrants – Not Applicable
Item 6 –	Investments
	(a) The registrants’ Schedules of Investments are included as part of the Report to Stockholders filed under Item 1 of this Form.
	(b) Not Applicable due to no such divestments during the semi-annual period covered since the previous Form N-CSR filing.
Item 7 –	Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies – Not Applicable
Item 8 –	Portfolio Managers of Closed-End Management Investment Companies – Not Applicable
Item 9 –	Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers – Not Applicable
Item 10 –	Submission of Matters to a Vote of Security Holders – There have been no material changes to these procedures.
Item 11 –	Controls and Procedures
	(a) The registrants’ principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrants’ disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the “1940 Act”)) are effective as of a date within 90 days of the filing of this report based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the 1940 Act and Rule 15d-15(b) under the Securities Exchange Act of 1934, as amended.
	(b) There were no changes in the registrants’ internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act) that occurred during the second fiscal quarter of the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrants’ internal control over financial reporting.
Item 12 –	Disclosure of Securities Lending Activities for Closed-End Management Investment Companies – Not Applicable
Item 13 –	Exhibits attached hereto
	(a)(1) – Code of Ethics – Not Applicable to this semi-annual report
	(a)(2) – Certifications – Attached hereto
	(a)(3) – Not Applicable

2

(a)(4) – Not Applicable

(b) –   Certifications – Attached hereto

3

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, each registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Funds For Institutions Series and Master Institutional Money Market LLC

By:	/s/ John M. Perlowski
	John M. Perlowski
	Chief Executive Officer (principal executive officer) of
	Funds For Institutions Series and Master Institutional Money Market LLC
Date:	January 4, 2019

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of each registrant and in the capacities and on the dates indicated.

By:	/s/ John M. Perlowski
	John M. Perlowski
	Chief Executive Officer (principal executive officer) of
	Funds For Institutions Series and Master Institutional Money Market LLC
Date:	January 4, 2019
By:	/s/ Neal J. Andrews
	Neal J. Andrews
	Chief Financial Officer (principal financial officer) of
	Funds For Institutions Series and Master Institutional Money Market LLC
Date:	January 4, 2019

4