Blackrock Municipal Income Investment Quality Trust (BAF) Form 4 BLACKROCK MUNICIPAL INCOME INVESTMENT QUALITY TRUST / Michael J Castellano ownership change

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Castellano Michael J

(Last) (First) (Middle)

55 EAST 52ND STREET

(Street)

NEW YORK NY 10055

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BLACKROCK MUNICIPAL INCOME INVESTMENT QUALITY TRUST [ BAF ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
03/08/2021

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/08/2021		J(1)		700	D	(1)	0	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Effective as of March 8, 2021, BlackRock Municipal Income Investment Quality Trust (the "Target Fund") was reorganized into BlackRock MuniHoldings Fund, Inc. (the "Acquiring Fund"). In the Reorganization, common shareholders of the Target Fund received common shares of the Acquiring Fund having a value equal to the aggregate NAV of the Target Fund common shares surrendered as determined at the close of business on March 5, 2021, less the costs of the Reorganization. As of March 5, 2021, the Target Fund reported a NAV per share of $15.2503 and the Acquiring Fund reported a NAV per share of $16.9927. The conversion ratio for the Target Fund's common shares was 0.89746185. In the Reorganization, Michael J. Castellano received 627 common shares (and cash for fractional shares, if any) of the Acquiring Fund in exchange for his 700 common shares of the Target Fund.

Remarks:

	/s/ Dean A. Caruvana as Attorney-in-Fact	03/10/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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