Compass (COMP) 10-Q 1 Nov 24 2024 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2024	Oct. 28, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-40291
Entity Registrant Name	COMPASS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	30-0751604
Entity Address, Address Line One	110 Fifth Avenue, 4th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10011
City Area Code	212
Local Phone Number	913-9058
Title of 12(g) Security	Class A Common Stock, $0.00001 par value per share
Trading Symbol	COMP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		510,307,191
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001563190
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets
Cash and cash equivalents	$ 211.2	$ 166.9
Accounts receivable, net of allowance of $7.0 and $8.6, respectively	45.8	36.6
Compass Concierge receivables, net of allowance of $10.4 and $13.2, respectively	34.8	24
Other current assets	38.7	54.5
Total current assets	330.5	282
Property and equipment, net	132.4	151.7
Operating lease right-of-use assets	392.4	408.5
Intangible assets, net	82.7	77.6
Goodwill	234.1	209.8
Other non-current assets	27.7	30.7
Total assets	1,199.8	1,160.3
Current liabilities
Accounts payable	14.3	18.4
Commissions payable	85.4	59.6
Accrued expenses and other current liabilities	132.4	90.8
Current lease liabilities	98.7	98.9
Total current liabilities	358.3	292.5
Non-current lease liabilities	382.3	410.2
Other non-current liabilities	28.1	25.6
Total liabilities	768.7	728.3
Commitments and contingencies (Note 6)
Stockholders’ equity
Common stock, $0.00001 par value, 13,850,000,000 shares authorized at September 30, 2024 and December 31, 2023; 507,581,054 shares issued and outstanding at September 30, 2024; 484,893,266 shares issued and outstanding at December 31, 2023	0	0
Additional paid-in capital	3,059.7	2,946.5
Accumulated deficit	(2,631.7)	(2,517.8)
Total Compass, Inc. stockholders’ equity	428	428.7
Non-controlling interest	3.1	3.3
Total stockholders’ equity	431.1	432
Total liabilities and stockholders’ equity	1,199.8	1,160.3
Concierge credit facility
Current liabilities
Concierge credit facility	$ 27.5	$ 24.8

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Allowance for credit loss on accounts receivable, current	$ 7	$ 8.6
Allowance for credit loss on financing receivable, current	$ 10.4	$ 13.2
Common stock par or stated value per share (in dollars per share)	$ 0.00001	$ 0.00001
Common stock shares authorized (in shares)	13,850,000,000	13,850,000,000
Common stock, issued (in shares)	507,581,054	484,893,266
Common stock, outstanding (in shares)	507,581,054	484,893,266

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Revenue	$ 1,494	$ 1,337.4	$ 4,248.7	$ 3,788.6
Operating expenses:
Commissions and other related expense	1,227.7	1,096.2	3,495.3	3,111.1
Sales and marketing	88.2	103.9	276.5	332.5
Operations and support	84.4	83.2	246.5	247.3
Research and development	47.5	45.8	141.9	140.1
General and administrative	27.4	24.2	132.5	93.3
Restructuring costs	1.7	1.7	7.5	27.7
Depreciation and amortization	20.5	21.3	62.7	68.5
Total operating expenses	1,497.4	1,376.3	4,362.9	4,020.5
Loss from operations	(3.4)	(38.9)	(114.2)	(231.9)
Investment income, net	2.2	1.5	4.7	6.9
Interest expense	(1.5)	(1.9)	(4.6)	(9.2)
Loss before income taxes and equity in income (loss) of unconsolidated entity	(2.7)	(39.3)	(114.1)	(234.2)
Income tax benefit	0.3	0.5	0.7	0.5
Equity in income (loss) of unconsolidated entity	0.5	(0.4)	(0.7)	(2.6)
Net loss	(1.9)	(39.2)	(114.1)	(236.3)
Net loss (income) attributable to non-controlling interests	0.2	(0.2)	0.2	(1.3)
Net loss attributable to Compass, Inc.	$ (1.7)	$ (39.4)	$ (113.9)	$ (237.6)
Net loss per share attributable to Compass, Inc., basic (in dollars per share)	$ 0	$ (0.08)	$ (0.23)	$ (0.52)
Net loss per share attributable to Compass, Inc., diluted (in dollars per share)	$ 0	$ (0.08)	$ (0.23)	$ (0.52)
Weighted-average shares used in computing net loss per share attributable to Compass, Inc., basic (in shares)	505,993,014	470,945,736	498,247,783	460,730,792
Weighted-average shares used to compute net loss per share attributable to Compass, Inc., diluted (in shares)	505,993,014	470,945,736	498,247,783	460,730,792

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Millions	Total	2022 Agent Equity Program	Common Stock	Common Stock 2022 Agent Equity Program	Additional Paid-in Capital	Additional Paid-in Capital 2022 Agent Equity Program	Accumulated Deficit	Total Compass, Inc. Stockholders’ Equity	Total Compass, Inc. Stockholders’ Equity 2022 Agent Equity Program	Non-controlling Interest
Beginning balance (in shares) at Dec. 31, 2022			438,098,194
Beginning balance at Dec. 31, 2022	$ 520.7				$ 2,713.6		$ (2,196.5)	$ 517.1		$ 3.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(236.3)						(237.6)	(237.6)		1.3
Issuance of common stock in connection with acquisitions (in shares)			3,215,610
Issuance of common stock in connection with acquisitions	10.6				10.6			10.6
Issuance of common stock upon exercise of stock options (in shares)			2,745,170
Issuance of common stock upon exercise of stock options	4.2				4.2			4.2
Issuance of common stock upon settlement of RSUs, net of taxes withheld (in shares)			9,919,619
Issuance of common stock upon settlement of RSUs, net of taxes withheld	(17.9)				(17.9)			(17.9)
Vesting of early exercised stock options	0.4				0.4			0.4
Issuance of common stock in connection with the 2022 Agent Equity Program (in shares)				14,147,480
Issuance of common stock in connection with the 2022 Agent Equity Program		$ 53.3				$ 53.3			$ 53.3
Issuance of common stock under the Employee Stock Purchase Plan (in shares)			759,835
Issuance of common stock under the Employee Stock Purchase Plan	2.5				2.5			2.5
Issuance of common stock in connection with the Strategic Transaction (in shares)			8,957,910
Issuance of common stock in connection with the Strategic Transaction	30				30			30
Stock-based compensation	111.4				111.4			111.4
Other activity related to non-controlling interests	(1.5)									(1.5)
Ending balance (in shares) at Sep. 30, 2023			477,843,818
Ending balance at Sep. 30, 2023	477.4				2,908.1		(2,434.1)	474		3.4
Beginning balance (in shares) at Jun. 30, 2023			462,987,617
Beginning balance at Jun. 30, 2023	451.7				2,842.3		(2,394.7)	447.6		4.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(39.2)						(39.4)	(39.4)		0.2
Issuance of common stock in connection with acquisitions (in shares)			637,406
Issuance of common stock in connection with acquisitions	2.4				2.4			2.4
Issuance of common stock upon exercise of stock options (in shares)			648,062
Issuance of common stock upon exercise of stock options	1.3				1.3			1.3
Issuance of common stock upon settlement of RSUs, net of taxes withheld (in shares)			4,221,908
Issuance of common stock upon settlement of RSUs, net of taxes withheld	(7.6)				(7.6)			(7.6)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)			390,915
Issuance of common stock under the Employee Stock Purchase Plan	1.1				1.1			1.1
Issuance of common stock in connection with the Strategic Transaction (in shares)			8,957,910
Issuance of common stock in connection with the Strategic Transaction	30				30			30
Stock-based compensation	38.6				38.6			38.6
Other activity related to non-controlling interests	(0.9)									(0.9)
Ending balance (in shares) at Sep. 30, 2023			477,843,818
Ending balance at Sep. 30, 2023	$ 477.4				2,908.1		(2,434.1)	474		3.4
Beginning balance (in shares) at Dec. 31, 2023	484,893,266		484,893,266
Beginning balance at Dec. 31, 2023	$ 432				2,946.5		(2,517.8)	428.7		3.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(114.1)						(113.9)	(113.9)		(0.2)
Issuance of common stock in connection with acquisitions (in shares)			6,583,051
Issuance of common stock in connection with acquisitions	$ 26.6				26.6			26.6
Issuance of common stock upon exercise of stock options (in shares)	3,258,748		3,258,748
Issuance of common stock upon exercise of stock options	$ 5.9				5.9			5.9
Issuance of common stock upon settlement of RSUs, net of taxes withheld (in shares)			12,124,714
Issuance of common stock upon settlement of RSUs, net of taxes withheld	(21.8)				(21.8)			(21.8)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)			721,275
Issuance of common stock under the Employee Stock Purchase Plan	2.2				2.2			2.2
Stock-based compensation	$ 100.3				100.3			100.3
Ending balance (in shares) at Sep. 30, 2024	507,581,054		507,581,054
Ending balance at Sep. 30, 2024	$ 431.1				3,059.7		(2,631.7)	428		3.1
Beginning balance (in shares) at Jun. 30, 2024			501,172,106
Beginning balance at Jun. 30, 2024	401.7				3,028.4		(2,630)	398.4		3.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1.9)						(1.7)	(1.7)		(0.2)
Issuance of common stock in connection with acquisitions (in shares)			941,394
Issuance of common stock in connection with acquisitions	4.1				4.1			4.1
Issuance of common stock upon exercise of stock options (in shares)			554,627
Issuance of common stock upon exercise of stock options	1.1				1.1			1.1
Issuance of common stock upon settlement of RSUs, net of taxes withheld (in shares)			4,575,570
Issuance of common stock upon settlement of RSUs, net of taxes withheld	(7.7)				(7.7)			(7.7)
Issuance of common stock under the Employee Stock Purchase Plan (in shares)			337,357
Issuance of common stock under the Employee Stock Purchase Plan	1.1				1.1			1.1
Stock-based compensation	$ 32.7				32.7			32.7
Ending balance (in shares) at Sep. 30, 2024	507,581,054		507,581,054
Ending balance at Sep. 30, 2024	$ 431.1				$ 3,059.7		$ (2,631.7)	$ 428		$ 3.1

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities
Net loss	$ (114.1)	$ (236.3)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	62.7	68.5
Stock-based compensation	96.3	121.9
Equity in loss of unconsolidated entity	0.7	2.6
Change in acquisition related contingent consideration	1.3	1.1
Bad debt expense	(0.1)	4.6
Amortization of debt issuance costs	0.5	0.6
Changes in operating assets and liabilities:
Accounts receivable	(6.9)	(8.3)
Compass Concierge receivables	(11.1)	7.9
Other current assets	16	13.6
Other non-current assets	4.6	11.5
Operating lease right-of-use assets and operating lease liabilities	(13.1)	7.6
Accounts payable	(5.6)	(5.8)
Commissions payable	25	29
Accrued expenses and other liabilities	34.8	(5.7)
Net cash provided by operating activities	91	12.8
Investing Activities
Investment in unconsolidated entity	(2)	0
Capital expenditures	(11.9)	(8.9)
Payments for acquisitions, net of cash acquired	(18.9)	0.7
Net cash used in investing activities	(32.8)	(8.2)
Financing Activities
Proceeds from exercise of stock options	5.9	4.2
Proceeds from issuance of common stock under Employee Stock Purchase Plan	2.2	2.5
Taxes paid related to net share settlement of equity awards	(21.8)	(17.9)
Proceeds from issuance of common stock in connection with the Strategic Transaction	0	32.3
Payments related to acquisitions, including contingent consideration	(2.9)	(12.1)
Other	0	(1.5)
Net cash used in financing activities	(13.9)	(146.5)
Net increase (decrease) in cash and cash equivalents	44.3	(141.9)
Cash and cash equivalents at beginning of period	166.9	361.9
Cash and cash equivalents at end of period	211.2	220
Supplemental disclosures of cash flow information:
Cash paid for interest	2.8	8
Supplemental non-cash information:
Issuance of common stock for acquisitions	26.6	10.6
Concierge credit facility
Financing Activities
Proceeds from drawdowns on credit facility	38	44.7
Repayments of drawdowns on credit facility	(35.3)	(48.7)
Revolving credit facility
Financing Activities
Proceeds from drawdowns on credit facility	0	75
Repayments of drawdowns on credit facility	$ 0	$ (225)

Business and Basis of Presentat

Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	Business and Basis of Presentation Description of the Business Compass, Inc. (the “Company”) was incorporated in Delaware on October 4, 2012 under the name Urban Compass, Inc. On January 8, 2021, the board of directors approved a change to the Company’s name from Urban Compass, Inc. to Compass, Inc. On April 6, 2021, the Company completed its initial public offering (“IPO”) and the Company’s Class A common stock began trading on the New York Stock Exchange on April 1, 2021 under the symbol “COMP”. The Company provides an end-to-end platform that empowers its residential real estate agents to deliver exceptional service to seller and buyer clients. The Company’s platform includes an integrated suite of cloud-based software for customer relationship management, marketing, client service and other critical functionality, all custom-built for the real estate industry, which enables the Company’s core brokerage services. The platform also uses proprietary data, analytics, artificial intelligence, and machine learning to deliver high value recommendations and outcomes for Compass agents and their clients. The Company’s agents are independent contractors who affiliate their real estate licenses with the Company, operating their businesses on the Company’s platform and under the Compass brand. The Company generates revenue from clients through its agents by assisting home sellers and buyers in listing, marketing, selling and finding homes as well as through the provision of services adjacent to the transaction, like title and escrow services, which comprise a smaller portion of the Company’s revenue to date. The Company currently generates substantially all of its revenue from commissions paid by clients at the time that a home is transacted. Basis of Presentation The condensed consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s condensed consolidated financial statements were prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) and include the assets, liabilities, revenues and expenses of all controlled subsidiaries. The condensed consolidated statements of operations include the results of entities acquired from the date of each respective acquisition. Interests held by third parties in consolidated subsidiaries are presented as non-controlling interests, which represents the non-controlling stockholders’ interests in the underlying net assets of the Company’s consolidated subsidiaries. For entities where the Company does not have a controlling interest (financial or operating), the investments in such entities are accounted for using the equity method. The Company applies the equity method of accounting when it has the ability to exercise significant influence over the operating and financial policies of an investee. The Company measures all other investments at fair value with changes in fair value recognized in net income or in the case that an equity investment does not have readily determinable fair values, at cost minus impairment (if any) plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment. The unaudited interim condensed consolidated financial statements and related disclosures have been prepared by management on a basis consistent with the annual consolidated financial statements and, in the opinion of management, include all adjustments necessary for a fair statement of the interim periods presented. The results of the interim periods presented are not necessarily indicative of the results expected for the full year. Certain information and notes normally included in financial statements prepared in accordance with GAAP have been condensed or omitted under the SEC’s rules and regulations. Accordingly, the unaudited condensed consolidated financial statements and notes included herein should be read in conjunction with the Company’s audited consolidated financial statements and the related notes for the year ended December 31, 2023 included in the 2023 Form 10-K. Liquidity Throughout 2023 and through the first nine months of 2024, a number of macroeconomic conditions contributed to a slowdown in the U.S. residential real estate market. In response to these conditions, the Company enacted various restructuring actions designed to improve the alignment between the Company’s organizational structure and its long-term business strategy, drive cost efficiencies enabled by the Company’s technology and other competitive advantages and continue to drive toward profitability and positive free cash flow. Additionally, as part of its nationwide class action settlement of the antitrust claims, NAR agreed to implement certain industry-wide practice changes, including, but not limited to, prohibiting buyer brokers' offers of compensation from being included in listings on Multiple Listing Services and requiring a buyer to enter into a written agreement with their agent that would set forth the buyer broker's fee before showing the buyer a property. These changes went into effect in mid-August. While the Company continues to assess the effects of the ongoing slowdown and the recent industry-wide changes on its business and financial results, the ultimate impact will depend on future developments, which are highly uncertain and difficult to predict, as well as the actions that the Company has taken, or will take, to minimize any current and future impact on its revenue, profitability, or liquidity. As of September 30, 2024 and December 31, 2023, the Company held cash and cash equivalents of approximately $211.2 million and $166.9 million, respectively. Additionally, the Company has a Revolving Credit Facility that matures in March 2026, which it can draw upon provided it maintains continued compliance with certain financial and non-financial covenants. As of September 30, 2024, the Company had $295.1 million available to be drawn under the Revolving Credit Facility. Further, the Company is in compliance with each of the financial and non-financial covenants under the Revolving Credit Facility. See Note 5 — "Debt" for further details. The Company's operating cash flows vary depending on the seasonality of the real estate business. The Company believes that it will have sufficient liquidity from cash on hand, its Revolving Credit Facility and future operations to sustain its business operations for the next twelve months and beyond.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make judgments, estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and reported amounts of revenue and expenses during the reporting periods covered by the condensed consolidated financial statements and accompanying notes. These judgments, estimates and assumptions are used for, but not limited to (i) valuation of the Company’s common stock and stock awards, (ii) fair value of acquired intangible assets and goodwill, (iii) fair value of contingent consideration arrangements in connection with business combinations, (iv) incremental borrowing rate used for the Company’s operating leases, (v) useful lives of long-lived assets, (vi) impairment of intangible assets and goodwill, (vii) allowance for Compass Concierge receivables and (viii) income taxes and certain deferred tax assets. The Company determines its estimates and judgments based on historical experience and on various other assumptions that it believes are reasonable under the circumstances. However, actual results could differ from these estimates and these differences may be material. Business Combinations Business combinations are accounted for under the acquisition method of accounting. This method requires, among other things, allocation of the fair value of purchase consideration to the tangible and intangible assets acquired and liabilities assumed at their estimated fair values on the acquisition date. The excess of the fair value of purchase consideration over the values of these identifiable assets and liabilities is recorded as goodwill. When determining the fair value of assets acquired and liabilities assumed, management makes estimates and assumptions, especially with respect to intangible assets. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and unpredictable and, as a result, actual results may differ from estimates. During the measurement period, not to exceed one year from the date of acquisition, the Company may record adjustments to the assets acquired and liabilities assumed, with a corresponding offset to goodwill if new information is obtained related to facts and circumstances that existed as of the acquisition date. After the measurement period, any subsequent adjustments are reflected in the condensed consolidated statements of operations. Acquisition costs, consisting primarily of third-party legal and consulting fees, are expensed as incurred. Stock-Based Compensation The Company measures compensation expense for all stock-based awards based on the estimated fair value of the awards on the date of grant. Compensation expense is generally recognized as expense on a straight-line basis over the service period based on the vesting requirements generally ranging from one For stock options, which the Company issues to employees, affiliated agents and in certain cases in connection with business combinations, the Company generally estimates the fair value using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (1) the fair value of common stock, (2) the expected stock price volatility, (3) the expected term of the award, (4) the risk-free interest rate and (5) expected dividends. The Company also issues RSUs to employees, and to affiliated agents and in certain cases in connection with business combinations. In addition to the issuance of RSUs to agents as equity compensation for the provision of services, the Company previously offered RSUs to affiliated agents through its Agent Equity Program. The Agent Equity Program offered affiliated agents the ability to elect to have a portion of their commissions earned during a calendar year to be paid in the form of RSUs. RSUs issued in connection with the Agent Equity Program were granted at the beginning of the year following the calendar year in which the commissions were earned and are subject to the terms and conditions of the 2012 Stock Incentive Plan and the 2021 Equity Incentive Plan, as applicable. The Company discontinued the Agent Equity Program following the issuance of RSUs during the first quarter of 2023 related to the 2022 Agent Equity Program. For RSUs granted in connection with the 2022 Agent Equity Program the Company determined the value of the stock-based compensation expense at the time the underlying commission was earned and recognized the associated expense on a straight-line basis over the requisite service periods beginning on the closing date of the underlying real estate commission transactions. The stock-based compensation expense was recorded as a liability throughout the service periods and was reclassified to Additional paid-in capital at the end of the vesting period when the underlying RSUs were issued. On a limited basis, the Company has issued stock options and RSUs that contain service, performance and market-based vesting conditions. Such awards were valued using a Monte Carlo simulation and the underlying expense will be recognized as the associated vesting conditions are met. New Accounting Pronouncements In December 2023, the FASB issued ASU 2023-09, Income Taxes - Improvements to Income Tax Disclosures . This standard includes enhanced income tax disclosures primarily related to the effective tax rate reconciliation and income taxes paid for annual periods. The amendments in this update are effective for public companies with fiscal years beginning after December 15, 2024, with early adoption permitted. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which is intended to improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant expenses. The update will require public entities to disclose significant segment expenses that are regularly provided to the chief operating decision maker and included within segment profit and loss. The amendments are effective for the Company's annual periods beginning January 1, 2024, and interim periods beginning January 1, 2025, with early adoption permitted, and will be applied retrospectively to all prior periods presented in the financial statements. We are currently evaluating the impact of the adoption of this standard to determine its impact on the Company's disclosures.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Acquisitions	Acquisitions During the three months ended June 30, 2024, the Company completed the acquisition of 100% of the ownership interests in Latter & Blum Holdings, LLC and Parks Village Nashville, LLC, two residential real estate brokerages, and during the three months ended March 31, 2024, the Company completed the acquisition of 100% ownership interest in a title insurance and escrow settlement services company. The purpose of these acquisitions was to expand the Company’s existing brokerage business and title and escrow presence in key domestic markets. The Company has accounted for these acquisitions as business combinations. The consideration for the acquisitions completed during the nine months ended September 30, 2024 is comprised of $26.1 million in the Company's Class A common stock, $21.3 million of cash paid at or near closing, net of cash acquired, an additional $2.7 million to be paid in cash and the Company's Class A common stock at a later date and an estimated $7.1 million of additional Class A common stock or cash that may be paid contingent on certain earnings-based targets being met at various payment dates through 2027. Payments in excess of the original estimate may impact the Company's statement of operations in future periods. The future consideration amounts were recorded within Accrued expenses and other current liabilities and Other non-current liabilities in the condensed consolidated balance sheet. For the nine months ended September 30, 2024, the fair value of the assets acquired and the liabilities assumed, related to the 2024 acquisitions, primarily resulted in the recognition of: $28.7 million of customer relationships; $2.4 million of trademark intangible assets; $20.1 million of other current and non-current assets; and $18.9 million of current and non- current liabilities. The excess of the aggregate purchase price over the aggregate fair value of the acquired net assets was recorded as goodwill of $24.9 million. Goodwill represents the expected synergies from combining the acquired assets and the operations of the acquirer as well as the intangible assets that do not qualify for separate recognition. The acquired intangible assets are being amortized over the estimated useful lives of approximately 5 to 6 years. Approximately $9.8 million of the goodwill recorded during the nine months ended September 30, 2024 is deductible for tax purposes. The amount of tax-deductible goodwill may increase in the future to approximately $17.0 million dependent on the payment of certain contingent consideration arrangements. These amounts are not expected to have an impact on the income tax provision while the Company maintains a full valuation allowance on its U.S. deferred tax assets. The Company has recorded the preliminary purchase price allocations as of the acquisition dates and expects to finalize its analysis within the measurement period (up to one year from each of the respective acquisition dates) of the transactions. Any adjustments during the measurement periods would have a corresponding offset to goodwill. Upon conclusion of the measurement periods or final determination of the values of assets acquired or liabilities assumed, any subsequent adjustments are recorded to the consolidated statements of operations. Pro forma revenue and earnings for this acquisition have not been presented because the acquisition is not material to the Company’s consolidated revenue and results of operations. Contingent Consideration Contingent consideration represents obligations of the Company to transfer cash and common stock to the sellers of certain acquired businesses in the event that certain targets and milestones are met. As of September 30, 2024, the undiscounted estimated payment under these arrangements was $39.7 million. Changes in contingent consideration measured at fair value on a recurring basis were as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Opening balance $ 26.9 $ 17.6 $ 20.9 $ 14.0 Acquisitions and measurement period adjustments (0.3) 4.0 7.1 12.8 Payments (0.4) (3.3) (2.7) (9.1) Changes in fair value included in net loss 0.4 0.5 1.3 1.1 Closing balance $ 26.6 $ 18.8 $ 26.6 $ 18.8 Other Acquisition-Related Arrangements

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	Fair Value of Financial Assets and Liabilities The Company’s cash and cash equivalents of $211.2 million and $166.9 million as of September 30, 2024 and December 31, 2023, respectively, are held in cash and money market funds, which are classified as Level 1 within the fair value hierarchy because they are valued using quoted prices in active markets. These are the Company’s only Level 1 financial instruments. The Company does not hold any Level 2 financial instruments. The Company’s contingent consideration liabilities of $26.6 million and $20.9 million as of September 30, 2024 and December 31, 2023, respectively, are the Company’s only Level 3 financial instruments. See Note 3 – “Acquisitions” for changes in contingent consideration for the three and nine months ended September 30, 2024 and 2023. The following table presents the balances of contingent consideration as presented in the condensed consolidated balance sheets (in millions): September 30, 2024 December 31, 2023 Accrued expenses and other current liabilities $ 3.1 $ 4.5 Other non-current liabilities 23.5 16.4 Total contingent consideration $ 26.6 $ 20.9 There were no transfers of financial instruments between Level 1, Level 2 and Level 3 during the periods presented. Level 3 Financial Liabilities

Debt

Debt	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Debt	Debt Concierge Credit Facility In July 2020, the Company entered into a Revolving Credit and Security Agreement (the “Concierge Facility”) with Barclays Bank PLC, as administrative agent, and the several lenders party thereto, which was subsequently amended on July 29, 2021, August 5, 2022 and August 4, 2023. The Concierge Facility provides for a $75.0 million revolving credit facility and is solely used to finance, in part, the Company’s Compass Concierge Program. The Concierge Facility is secured primarily by the Concierge Receivables and cash of the Compass Concierge Program. Borrowings under the Concierge Facility bear interest at the term SOFR rate plus a margin of 2.75%. The two year commitment fee is 0.35% if the Concierge Facility is utilized greater than 50% and 0.50%, if the Concierge Facility is utilized less than 50%. On August 4, 2023, the revolving period under the Concierge Facility was extended to August 3, 2025. The interest rate on the drawn down portion of the Concierge Facility was 8.00% as of September 30, 2024. Pursuant to the Concierge Facility, the principal amount, if any, is payable in full in January 2026, unless earlier terminated or extended. The Company has the option to repay the borrowings under the Concierge Facility without premium or penalty prior to maturity. The Concierge Facility contains customary affirmative covenants, such as financial statement reporting requirements, as well as covenants that restrict the Company's ability to, among other things, incur additional indebtedness, sell certain receivables, declare dividends or make certain distributions, and undergo a merger or consolidation or certain other transactions. Additionally, in the event that the Company fails to comply with certain financial covenants that require the Company to meet certain liquidity-based measures, the commitments under the Concierge Facility will automatically be reduced to zero and the Company will be required to repay any outstanding loans under the Concierge Facility. As of September 30, 2024, the Company was in compliance with the covenants under the Concierge Facility. The Concierge Facility includes customary events of default that include, among other things, nonpayment of principal, interest or fees, inaccuracy of representations and warranties, violation of certain covenants, bankruptcy and insolvency events, material judgments and change of control. The occurrence of an event of default could result in the acceleration of the obligations and/or the increase in the applicable interest rate under the Concierge Facility. Revolving Credit Facility In March 2021, the Company entered into a Revolving Credit and Guaranty Agreement (the “Revolving Credit Facility”) with Barclays Bank PLC, as administrative agent and as collateral agent (the "Administrative Agent"), and certain other lenders, which was subsequently amended on May 1, 2023. The Revolving Credit Facility provides for a $350.0 million revolving credit facility, subject to the terms and conditions of the Revolving Credit Facility. The Revolving Credit Facility also includes a letter of credit sublimit which is the lesser of (i) $125.0 million and (ii) the aggregate unused amount of the revolving commitments then in effect under the Revolving Credit Facility. The Company’s obligations under the Revolving Credit Facility are guaranteed by certain of the Company’s subsidiaries and are secured by a first priority security interest in substantially all of the assets of the Company and the Company’s subsidiary guarantors. Borrowings under the Revolving Credit Facility bear interest, at the Company’s option, at either (i) a floating rate per annum equal to the base rate plus a margin of 0.50% or (ii) a rate per annum equal to the secured overnight financing rate ("SOFR") plus a margin of 1.50%. The base rate is equal to the highest of (a) the prime rate as quoted by The Wall Street Journal, (b) the federal funds effective rate plus 0.50%, (c) the SOFR term rate for a one-month interest period plus 1.00% and (d) 1.00%. The SOFR term rate is determined by the Administrative Agent as the forward-looking term rate plus a 0.10% adjustment. During an event of default under the Revolving Credit Facility, the applicable interest rates are increased by 2.0% per annum. The Company is also obligated to pay other customary fees for a credit facility of this type, including a commitment fee on a quarterly basis based on amounts committed but unused under the Revolving Credit Facility of 0.175% per annum, fees associated with letters of credit and administrative and arrangement fees. The principal amount, if any, is payable in full in March 2026, unless earlier terminated or extended. The Company has the option to repay the Company’s borrowings, and to permanently reduce the loan commitments in whole or in part, under the Revolving Credit Facility without premium or penalty prior to maturity. As of September 30, 2024, there were no borrowings outstanding under the Revolving Credit Facility and outstanding letters of credit under the Revolving Credit Facility totaled approximately $54.9 million. The Revolving Credit Facility contains customary representations, warranties, financial covenants applicable to the Company and its restricted subsidiaries, affirmative covenants, such as financial statement reporting requirements, and negative covenants which restrict their ability, among other things, to incur liens and indebtedness, make certain investments, declare dividends, dispose of, transfer or sell assets, make stock repurchases and consummate certain other matters, all subject to certain exceptions. The financial covenants require that (i) the Company maintains liquidity of at least $150.0 million as of the last day of each fiscal quarter and each date of a credit extension and (ii) the Company’s consolidated total revenue as of the last day of each fiscal quarter be equal to or greater than the specified amount corresponding to such period. Minimum liquidity is defined as unused amounts under the $350.0 million Revolving Credit Facility plus the unrestricted cash of Compass and its restricted subsidiaries. The minimum required consolidated revenue threshold for the trailing four fiscal quarters is $4,668.0 million during 2024 and thereafter. As of September 30, 2024, the Company was in compliance with the financial covenants under the Revolving Credit Facility.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings From time to time, the Company may be involved in disputes or regulatory inquiries that arise in the ordinary course of business. When the Company determines that a loss is both probable and reasonably estimable, a liability is recorded and disclosed if the amount is material to the Company’s business taken as a whole. When a material loss contingency is only reasonably possible, the Company does not record a liability, but instead discloses the nature and the amount of the claim and an estimate of the loss or range of loss, if such an estimate can reasonably be made. Legal costs related to the defense of loss contingencies are expensed as incurred. Claims or regulatory actions against the Company, whether meritorious or not, could have an adverse impact on the Company due to legal costs, diversion of management resources and other elements. Except as identified with respect to the matters below, the Company does not believe that the outcome of any individual existing legal or regulatory proceeding to which it is a party will have a material adverse effect on its results of operations, financial condition or overall business in each case, taken as a whole. Real Estate Commission Sell-Side Antitrust Litigation The Company and its subsidiaries have been named as defendants in eight putative class action lawsuits and one individual lawsuit (the "Antitrust Lawsuits") that allege, among other things, violations of Section 1 of the Sherman Act, 15 U.S.C. § 1. Four of the putative class action lawsuits, captioned Gibson, et al. v. National Association of Realtors, et al., No. 4:23-cv-00788-FJG (W.D. Mo.) (“Gibson”), filed on October 31, 2023, Grace v. National Association of Realtors, et al., No. 3:23-cv-06352 (N.D. Cal.) (“Grace”), filed on December 8, 2023, Fierro, et al. v. National Association of Realtors, et al., Case No. 2:24-cv-00449 (C.D. Cal.) (“Fierro”), filed on January 17, 2024, and Whaley v. Arizona Association of Realtors, Case No. 2:24-cv-00105 (D. Nev.) (“Whaley”), filed on January 15, 2024, name the Company as a defendant and allege, among other things, that certain trade associations, including the National Association of Realtors, multiple listing services, and real estate brokerages engaged in a continuing contract, combination, or conspiracy to unreasonably restrain interstate trade and commerce in violation of Section 1 of the Sherman Act, 15 U.S.C. § 1 by entering into a continuing agreement to require sellers of residential property to make inflated payments to brokers representing buyers. Umpa, et al. v. National Association of Realtors, et al., 4:23-cv-00945 (W.D. Mo.) (“Umpa”), filed on December 27, 2023, was consolidated into the Gibson matter on April 23, 2024. Boykin v. National Association of Realtors, et al., No. 2:24-cv-00340 (D. Nev.) (“Boykin”), filed on February 16, 2024, was terminated and consolidated into the Whaley matter on March 20, 2024. The plaintiffs in the Gibson and Umpa matters allege a nationwide scope, while the Grace and Fierro matters are limited in scope to Northern California and Southern California, respectively and the Whaley matter is limited in scope to Nevada. The Grace, Fierro and Whaley matters are stayed pending final approval of the settlement agreement. On December 27, 2023, plaintiffs in the Gibson and Umpa matters filed a motion before the United States Judicial Panel on Multidistrict Litigation (“JPML”), captioned In re Real Estate Commission Litigation, No. 48 (J.P.M.L.), seeking to transfer and consolidate for pretrial proceedings the Gibson, Umpa, Grace, March, QJ Team, Martin, and three additional putative class actions to which the Company has not been named as a party, to one multidistrict litigation. On April 12, 2024, the JPML denied consolidation at this time based on the procedural posture of the litigation and recent nationwide class settlements. O n March 21, 2024, the Company entered into a settlement agreement to resolve the Gibson and Umpa cases on a nationwide basis. The settlement resolves all claims in these cases and similar claims in other lawsuits alleging claims on behalf of sellers on a nationwide basis against the Company and its subsidiaries (collectively, the “Claims”) and releases the Company, its subsidiaries and affiliated agents from the Claims. Under the settlement agreement, the Company agreed to pay $57.5 million and make certain changes to its business practices. The Gibson and Umpa matters were stayed as to Compass on March 25, 2024. The court preliminarily approved the proposed settlement agreement on April 30, 2024. The Company’s motion for final approval of the settlement agreement was granted on October 31, 2024 and the settlement agreement is now effective. Plaintiffs may appeal the final approval ruling before December 2, 2024. Two of the putative class action lawsuits, March v. Real Estate Board of New York, et al., No. 1:23-cv-09995 (S.D.N.Y.) (“March”), filed on November 13, 2023, and Friedman v. Real Estate Board of New York, et al., Case No. 1:23-cv-09601 (S.D.N.Y.) (“Friedman”), filed on January 18, 2024, name the Company as a defendant and allege, among other things, that the Real Estate Board of New York, and a number of real estate brokerages engaged in a continuing contract, combination, or conspiracy to unreasonably restrain interstate trade and commerce in violation of Section 1 of the Sherman Act, 15 U.S.C. § 1 by entering into a continuing agreement to require sellers of residential property to make inflated payments to brokers representing buyers. The Friedman and March matters also allege violations of the Donnelly Act, N.Y. Gen. Bus. § 340, and the March matter further seeks injunctive relief pursuant to Section 16 of the Clayton Act, 15 U.S.C. § 26. The Friedman and March matters are limited in scope to the New York City boroughs of Brooklyn, and Manhattan, respectively. The March and Friedman matters are stayed pending final approval of the settlement agreement. One putative class action lawsuit, QJ Team, LLC, et al. v. Texas Association of Realtors, Inc., et al., No. 4:23-cv-01013 (E.D. Tx.) (“QJ Team”), filed on November 13, 2023, names Realty Austin, LLC, a subsidiary of the Company, as a defendant and alleges, among other things, that certain trade associations, including the Texas Association of Realtors, and a number of real estate brokerages engaged in a continuing contract, combination, or conspiracy to unreasonably restrain interstate trade and commerce in violation of Section 1 of the Sherman Act, 15 U.S.C. § 1 by entering into a continuing agreement to require sellers of residential property to make inflated payments to brokers representing buyers. Martin, et al. v. Texas Association of Realtors, Inc., et al., No. 423-cv-01104 (E.D. Tx.) (“Martin”), filed on December 14, 2023, was consolidated into the QJ Team matter on March 21, 2024. The QJ Team matter is stayed pending final approval of the settlement agreement. Wang v. National Ass’n of Realtors et al., Case No. 1:24-cv-02371 (S.D.N.Y.) (“Wang”), an individual lawsuit filed on March 28, 2024, names the Company as a defendant and alleges, among other things, that certain trade associations, including the National Association of Realtors and the Real Estate Board of New York, and a number of real estate brokerages engaged in a continuing contract, combination, or conspiracy to unreasonably restrain interstate trade and commerce in violation of Section 1 of the Sherman Act, 15 U.S.C. § 1 by entering into a continuing agreement to require sellers of residential property to make inflated payments to brokers representing buyers. Co-defendants in the Wang matter filed a Motion to Stay the matter on June 14, 2024, pending final approval of the settlement agreement. The Wang matter is stayed until November 26, 2024. During the three months ended March 31, 2024, the Company recognized an expense of $57.5 million within General and administrative expense in the condensed consolidated statements of operations in connection with the settlement agreement. 50% of the settlement was paid during the three months ended June 30, 2024. The remaining 50% is expected to be paid during the second quarter of 2025. Batton, et al. v. Compass, Inc., et al. Batton, et al. v. Compass, Inc., et al., No. 1:23-cv-15618 (N.D. Ill.) (“Batton II”), filed on November 2, 2023, names the Company and seven other brokerages as defendants and alleges that the defendants entered into a continuing contract, combination, or conspiracy to unreasonably restrain interstate trade and commerce in violation of Section 1 of the Sherman Act, 15 U.S.C. § 1 and state law antitrust statutes, violated state consumer protection statutes, and were unjustly enriched by industry rules that set the manner by which buyer’s brokers are compensated. The allegations in Batton II are substantially similar to those contained in the case captioned Batton, et al. v. National Association of Realtors, et al., No. 1:21-cv-00430 (N.D. Ill.) (“Batton I”), filed on January 25, 2021, which does not name the Company but names the National Association of Realtors and six other brokerages. The Company and the defendants in the Batton II matter filed a motion to dismiss the amended complaint on June 21, 2024. The plaintiffs filed an opposition to the motion to dismiss on August 5, 2024 and the Company and the defendants filed a reply on September 4, 2024. The Company is unable to predict the outcome of Batton II or to reasonably estimate the possible loss or range of loss, if any, arising from the claim asserted therein. The ultimate resolution of Batton II could have a material adverse effect on the Company’s financial position, results of operations, and cash flow. Letter of Credit Agreements The Company has irrevocable letters of credit with various financial institutions, primarily related to security deposits for leased facilities. As of September 30, 2024 and December 31, 2023, the Company was contingently liable for $54.9 million and $44.4 million, respectively, under these letters of credit. As of September 30, 2024, $54.9 million of these letters of credit were collateralized by the Revolving Credit Facility. As of December 31, 2023, $43.8 million and $0.6 million of these letters of credit were collateralized by the Revolving Credit Facility and the Company's cash and cash equivalents, respectively. Escrow and Trust Deposits As a service to its home buyers and sellers, the Company administers escrow and trust deposits, which represent undistributed amounts for the settlement of real estate transactions. The escrow and trust deposits totaled $246.1 million and $120.0 million as of September 30, 2024 and December 31, 2023, respectively. These deposits are not assets of the Company and therefore are excluded from the accompanying condensed consolidated balance sheets. However, the Company remains contingently liable for the disposition of these deposits.

Preferred Stock and Common Stoc

Preferred Stock and Common Stock	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Preferred Stock and Common stock	Preferred Stock and Common Stock Undesignated Preferred Stock In April 2021, the Company adopted a restated certificate of incorporation, which authorizes the Company to issue up to 25.0 million shares of undesignated preferred stock with a $0.00001 par value per share. As of September 30, 2024 and December 31, 2023, there are no shares of the Company’s preferred stock issued and outstanding. Common Stock In February 2021, the Company approved the establishment of Class C common stock and an agreement with the Company’s CEO to exchange his Class A common stock for Class C common stock. Any Class A common stock issued to the Company’s CEO from RSU awards granted prior to February 2021 are able to be exchanged for Class C common stock. Each share of Class C common stock is entitled to twenty votes per share and will be convertible at any time into one share of Class A common stock and will automatically convert into Class A common stock under certain “sunset” provisions. Other than certain permitted transfers for estate planning purposes, upon a transfer of Class C common stock, the Class C common stock will convert into Class A common stock. In April 2021, the Company adopted a restated certificate of incorporation and changed its authorized capital stock to consist of 12.5 billion shares of Class A common stock, 1.25 billion shares of Class B common stock and 100 million shares of Class C common stock. Each class has par value of $0.00001. The following tables reflect the authorized, issued and outstanding shares for each of the classes of common stock as of September 30, 2024 and December 31, 2023: September 30, 2024 Shares Shares Shares Class A common stock 12,500,000,000 491,822,267 491,822,267 Class B common stock 1,250,000,000 — — Class C common stock 100,000,000 15,758,787 15,758,787 Total 13,850,000,000 507,581,054 507,581,054 December 31, 2023 Shares Shares Shares Class A common stock 12,500,000,000 465,633,122 465,633,122 Class B common stock 1,250,000,000 — — Class C common stock 100,000,000 19,260,144 19,260,144 Total 13,850,000,000 484,893,266 484,893,266 Holders of Class A common stock are entitled to one vote per share. Holders of Class B common stock are not entitled to vote. Holders of Class C common stock are entitled to twenty votes per share. Each share of Class C common stock is convertible at any time at the option of the holder into one share of Class A common stock. Each share of Class C common stock will automatically convert into a share of Class A common stock upon sale or transfer, except for certain permitted transfers. Strategic Transaction In August 2023, the Company entered into a definitive asset purchase agreement with a Canadian real estate proptech company (the "Strategic Transaction") under which the Company received $32.3 million of cash in exchange for 9.0 million shares of Class A common stock and committed to make an additional contingent payment in the form of Class A common stock or cash, as determined by the Company. The contingent payment was dependent on a volume-weighted stock price target for the Company's Class A common stock and was payable up to a maximum of $5.5 million in May 2025 (unless the volume-weighted stock price target is triggered). During the three months ended June 30, 2024, the volume-weighted price target was met and the Company was released of its liability to make any additional payment in connection with this arrangement.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2012 Stock Incentive Plan In October 2012, the Company adopted the 2012 Stock Incentive Plan (the “2012 Plan”). Under the 2012 Plan, employees and non-employees could be granted stock options, RSUs and other stock-based awards. Generally, these awards were based on stock agreements with a maximum ten-year term for stock options and a maximum seven-year term for RSUs, subject to board approval. 2021 Equity Incentive Plan In February 2021, the Company’s board of directors and stockholders adopted and approved the 2021 Equity Incentive Plan (the “2021 Plan”), with an initial pool of 29.7 million shares of common stock available for granting stock-based awards plus any reserved shares of common stock not issued or subject to outstanding awards granted under the 2012 Plan. In addition, on January 1 st of each year beginning in 2022 and continuing through 2031, the aggregate number of shares of common stock authorized for issuance under the 2021 Plan shall be increased automatically by the number of shares equal to 5% of the total number of outstanding shares of common stock and outstanding shares of preferred stock (on an as converted to common stock basis) on the immediately preceding December 31 st , although the Company’s board of directors or one of its committees may reduce the amount of such increase in any particular year. The 2021 Plan became effective on March 30, 2021 and as of that date, the Company ceased granting new awards under the 2012 Plan and all remaining shares available under the 2012 Plan were transferred to the 2021 Plan. Effective January 1, 2024, the shares available for future grants were increased by an additional 24.2 million shares as a result of the annual increase provision described above. As of September 30, 2024, there were 59.7 million shares available for future grants under the 2021 Plan, inclusive of those shares transferred from the 2012 Plan. 2021 Employee Stock Purchase Plan In February 2021, the Company’s board of directors and stockholders adopted and approved the 2021 Employee Stock Purchase Plan (the “ESPP”), with an initial pool of 7.4 million shares of Class A common stock available for authorized purchase rights to the Company’s employees or to employees of its designated affiliates. In addition, on January 1 st of each year beginning in 2022 and continuing through 2031, the aggregate number of shares of common stock authorized for issuance under the ESPP shall be increased automatically by the number of shares equal to 1% of the total number of outstanding shares of common stock and outstanding shares of preferred stock (on an as converted to common stock basis) on the immediately preceding December 31 st , although the Company’s board of directors or one of its committees may reduce the amount of the increase in any particular year. No more than 150.0 million shares of common stock may be issued over the term of the ESPP, subject to certain exceptions set forth in the ESPP. Effective January 1, 2024, the authorized shares increased by 4.7 million shares as a result of the annual increase provision described above. As of September 30, 2024, 18.1 million shares of Class A common stock remain available for grant under the ESPP. The ESPP permits employees to purchase shares of the Company’s Class A common stock through payroll deductions accumulated during six-month offering periods up to a maximum value of $12,500 per offering period. The offering periods begin each February and August, or such other period determined by the Compensation Committee. On each purchase date, eligible employees may purchase the shares at a price per share equal to 85% of the lesser of (1) the fair market value of the Company’s Class A common stock on the first trading day of the offering period, or (2) the fair market value of the Company’s Class A common stock on the purchase date, as defined in the ESPP. During the nine months ended September 30, 2024, the Company issued 0.7 million shares of Class A common stock under the ESPP. The Company recognized $0.2 million and $0.7 million of stock-based compensation expense related to the ESPP during the three and nine months ended September 30, 2024, respectively, and $0.4 million and $1.0 million during the three and nine months ended September 30, 2023, respectively. As of September 30, 2024, $0.4 million has been withheld on behalf of employees for a future purchase under the ESPP. Stock Options A summary of stock option activity under the 2012 Plan and the 2021 Plan, including 1.1 million stock options that were granted outside of the 2012 Plan in 2019, is presented below (in millions, except share and per share amounts): Number of Weighted Average Weighted Average Aggregate Intrinsic Value (1) Balance as of December 31, 2023 40,527,848 $ 5.60 5.1 $ 20.2 Granted — — Exercised (3,258,748) 1.83 Forfeited (1,904,614) 6.62 Balance as of September 30, 2024 35,364,486 $ 5.89 4.6 $ 38.8 Exercisable and vested at September 30, 2024 32,751,775 $ 5.64 4.5 $ 38.3 (1) The aggregate intrinsic values have been calculated using the Company’s closing stock prices of $6.11 and $3.76 as of September 30, 2024 and December 31, 2023, respectively. During the nine months ended September 30, 2024 and 2023, the intrinsic value of options exercised was $7.3 million and $5.9 million, respectively. Restricted Stock Units A summary of RSU activity under the 2012 Plan and the 2021 Plan is presented below: Number of Awards Weighted Average Grant Date Fair Value Balance as of December 31, 2023 29,943,818 $ 5.15 Granted 24,238,196 3.62 Vested and converted to common stock (1) (18,204,182) 4.35 Forfeited (3,111,621) 4.61 Balance as of September 30, 2024 32,866,211 $ 4.52 (1) During the nine months ended September 30, 2024, the Company net settled all RSUs through which it issued an aggregate of 18.2 million shares of Class A common stock and withheld an aggregate of 6.1 million shares of Class A common st ock to satisfy $21.8 million of tax withholding obligations on behalf of the Company’s employees. Agent Equity Program In connection with the 2022 Agent Equity Program, the Company recognized a total of $53.3 million in stock-based compensation expense of which $41.7 million was recognized during the year ended December 31, 2022 and $11.6 million was recognized during the nine months ended September 30, 2023. In January 2023, the Company granted 14.1 million RSUs, which immediately vested and converted to Class A common stock in connection with the 2022 Agent Equity Program. Prior to the issuance of the underlying RSUs, the stock-based compensation expense associated with these awards was recorded as a liability and $53.3 million was ultimately reclassified to Additional paid-in capital at the end of the vesting period when the underlying RSUs were granted. Following the issuance of these RSUs, the Company discontinued the Agent Equity Program. Stock-Based Compensation Expense Total stock-based compensation expense included in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024 and 2023 is as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Commissions and other related expense $ — $ — $ — $ 11.6 Sales and marketing 7.8 8.8 24.0 26.4 Operations and support 4.2 4.5 12.3 11.6 Research and development 14.6 11.4 44.7 34.4 General and administrative 5.9 13.3 15.3 37.9 Total stock-based compensation expense $ 32.5 $ 38.0 $ 96.3 $ 121.9 As of September 30, 2024, unrecognized stock-based compensation expense totaled $138.0 million and is expected to be recognized over a weighted-average period of 2.0 years. The Company has not recognized any tax benefits from stock-based compensation as a result of the full valuation allowance maintained on its deferred tax assets.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recognized $0.3 million and $0.7 million of income tax benefit for the three and nine months ended September 30, 2024. This benefit resulted from a partial reduction in the valuation allowance related to the carryover tax basis in deferred tax liabilities from acquisitions netted with the recognition of deferred tax assets in India and state income tax expense. Additionally, the Company incurred current tax expense from its operations in India. The Company recognized a $0.5 million benefit from income taxes for the three and nine months ended September 30, 2023. The Company continues to maintain a full valuation allowance on all domestic net deferred tax assets based on numerous factors including estimated future taxable income and historic profitability. The Company had no material uncertain tax positions as of the period ended September 30, 2024 nor does it expect a substantial increase in the next 12 months. If applicable, the Company recognizes interest and penalties related to uncertain tax positions in the income tax provision. The U.S. is the Company’s only material tax jurisdiction. The Company is generally no longer subject to U.S. federal examination by the Internal Revenue Service (“IRS”) for years before 2015. The IRS and state taxing authorities can subject the Company to audit dating back to 2012 when the Company begins to utilize its net operating loss carryforwards.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Compass, Inc.	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Compass, Inc.	Net Loss Per Share Attributable to Compass, Inc. The Company computes net loss per share under the two-class method required for multiple classes of common stock and participating securities. The rights, including the liquidation and dividend rights, of the Class A common stock, Class B common stock and Class C common stock are substantially identical, other than voting rights. Accordingly, the net loss per share attributable to Compass, Inc. will be the same for Class A common stock, Class B common stock and Class C common stock on an individual or combined basis. The following table sets forth the computation of basic and diluted net loss per share attributable to Compass, Inc. (in millions, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net loss attributable to Compass, Inc. $ (1.7) $ (39.4) $ (113.9) $ (237.6) Denominator: Weighted-average shares used in computing net loss per share attributable to Compass, Inc., basic and diluted 505,993,014 470,945,736 498,247,783 460,730,792 Net loss per share attributable to Compass, Inc., basic and diluted $ (0.00) $ (0.08) $ (0.23) $ (0.52) The following participating securities were excluded from the computation of diluted net loss per share attributable to Compass, Inc. for the periods presented, because including them would have been anti-dilutive (on an as-converted basis): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Outstanding stock options 35,364,486 41,439,848 35,364,486 41,439,848 Outstanding RSUs 32,866,211 48,481,527 32,866,211 48,481,527 Shares subject to the Employee Stock Purchase Plan 336,429 685,943 336,429 685,943 Unvested early exercised stock options 1,660 29,070 1,660 29,070 Unvested common stock 115,895 — 115,895 — Contingent common stock to be issued in connection with the Strategic Transaction — 1,791,802 — 1,791,802 Total 68,684,681 92,428,190 68,684,681 92,428,190

Compass Concierge Receivables a

Compass Concierge Receivables and Allowance for Credit Losses	9 Months Ended
	Sep. 30, 2024
Receivables [Abstract]
Compass Concierge Receivables and Allowance for Credit Losses	Compass Concierge Receivables and Allowance for Credit Losses In 2018, the Company launched the Compass Concierge Program for home sellers who have engaged Compass as their exclusive listing agent. The initial program was based on a services model (“Concierge Classic”) provided by Compass Concierge, LLC (“Compass Concierge”), which included items such as consultation on suggested cosmetic updates or modifications to a specific property or guidance on securing licensed contractors or vendors to perform non-structural property improvements. The Concierge Classic program provided for the payment of the up-front costs of specified home improvement services provided by unrelated vendors. During 2022, the Company substantially ceased providing new payments under the Concierge Classic program. In 2019, the Compass Concierge Program was expanded to include a loan program underwritten by an independent third-party lender (the “Lender”) through a commercial arrangement with Compass Concierge (“Concierge Capital”). Under the Concierge Capital program, the Lender originates and services unsecured consumer loans to home sellers following its independent underwriting process pursuant to program-level criteria provided by the Company. The Company has no right or obligation with respect to any individual consumer loan originated by the Lender. Under the agreement, the Company has repayment rights against the Lender in connection with a corporate loan. Payment to the Company for these services under the Concierge Classic program or repayment of the loan funds under the Concierge Capital program is due upon the earlier of a successful home sale, the termination of the listing agreement or one year from the date in which costs were originally funded. Compass Concierge receivables (“Concierge Receivables”) are stated at the amount advanced to the home sellers, net of an estimated allowance for credit losses (“ACL”) in the accompanying condensed consolidated balance sheets. For the three and nine months ended September 30, 2024 and 2023, the Company did not recognize any material income from the Compass Concierge Program. The Company incurs service fees payable to the Lender and incurs bad debt expense in connection with the Compass Concierge Program. The Company manages its credit risk by establishing a comprehensive credit policy for the approval of new loans while monitoring and reviewing the performance of its existing Concierge Receivables. Factors considered include but are not limited to: • No negative liens or judgements on the property; • Seller’s available equity on the property; • Loan to listing price ratio; • FICO score (only for Concierge Capital program); and • Macroeconomic conditions. Credit Quality The Company monitors credit quality by evaluating various attributes and utilizes such information in its evaluation of the appropriateness of the ACL. Based on the Company’s experience, the key credit quality indicator is whether the underlying properties associated with the Concierge Receivables will be sold or not. Concierge Receivables associated with properties that are eventually sold have a lower credit risk than those that are associated with properties that are not sold. As of September 30, 2024 and December 31, 2023, the amount of outstanding Concierge Receivables related to unsold properties was approximately 98% and 97%, respectively. For Concierge Receivables where repayments have not been triggered (i.e., earlier of (i) sale of the property, (ii) termination of a listing agreement or (iii) 12 months from the date costs were originally funded), the Company establishes an estimate as to the percentage of underlying properties that will be sold based on historical data. This estimate is updated as of the end of each reporting period. Allowance for Credit Losses The Company maintains an ACL for the expected credit losses over the contractual life of the Concierge Receivables. The amount of ACL is based on ongoing, quarterly assessments by management. Historical loss experience is generally the starting point when the Company estimates the expected credit losses. The Company then considers whether (i) current conditions and economic conditions, (ii) future economic conditions and (iii) any potential changes in the Compass Concierge Program that are reasonable and supportable would impact its ACL. The following table summarizes the activity of the ACL for Concierge Receivables for the three and nine months ended September 30, 2024 (in millions): Three Months Ended September 30, 2024 Nine Months Ended September 30, 2024 Beginning of period $ 11.1 $ 13.2 Allowances 0.1 0.3 Net write-offs (0.8) (3.1) End of period $ 10.4 $ 10.4 Aging Status The Company generally considers Concierge Receivables to be past due after being outstanding for over 30 days after the initial billing. Changes in the Company’s estimate to the ACL are recorded through bad debt expense as Sales and marketing expense in the condensed consolidated statements of operations and individual accounts are charged against the allowance when all reasonable collection efforts are exhausted. The following table presents the aging analysis of Concierge Receivables as of September 30, 2024 (in millions): September 30, 2024 Current $ 40.7 31-90 days past due 1.4 Over 90 days past due 3.1 Total $ 45.2

Restructuring Activities

Restructuring Activities	9 Months Ended
	Sep. 30, 2024
Restructuring and Related Activities [Abstract]
Restructuring Activities	Restructuring Activities Beginning in 2022, the Company enacted certain workforce reductions, wound down Modus Technologies, Inc., terminated certain of its operating leases and took actions to reduce its occupancy costs, the most significant being the scaling down of its New York administrative office. The workforce reductions were part of a broader plan by the Company to take meaningful actions to improve the alignment between the Company’s organizational structure and its long-term business strategy, drive cost efficiencies enabled by the Company’s technology and other competitive advantages and continue to drive toward profitability and positive free cash flow. The lease termination costs were recognized as a result of the accelerated amortization of various right-of-use assets and other lease-related costs. These expenses have been presented within the Restructuring costs line in the condensed consolidated statements of operations. The Company incurred additional non-cash charges during the three and nine months ended September 30, 2024 and 2023 associated with the write-down of fixed assets for certain real estate leases that have been exited, or partially exited. These costs have been included within the Depreciation and amortization line in the condensed consolidated statements of operations. The following table summarizes the total costs incurred in connection with the Company's restructuring activities taken during the three and nine months ended September 30, 2024 and 2023 (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Severance related personnel costs $ — $ — $ — $ 8.9 Lease termination costs 1.7 1.7 7.5 18.8 Accelerated depreciation 0.1 — 1.9 5.3 Total expense $ 1.8 $ 1.7 $ 9.4 $ 33.0 The total costs incurred in connection with the Company's restructuring activities taken during the three and nine months ended September 30, 2024 and 2023 were included in the condensed consolidated statements of operations as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Restructuring costs $ 1.7 $ 1.7 $ 7.5 $ 27.7 Depreciation and amortization 0.1 — 1.9 5.3 Total expense $ 1.8 $ 1.7 $ 9.4 $ 33.0 The following table summarizes the estimated timing of the Company's future lease and lease-related payments, net of amounts contractually subleased, related to restructuring activities as of September 30, 2024 (in millions): Payment Due by Period Remaining 2024 $ 5.5 2025 11.4 2026 7.0 2027 5.7 Thereafter 7.7 Total $ 37.3

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (1.7)	$ (39.4)	$ (113.9)	$ (237.6)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The condensed consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The Company’s condensed consolidated financial statements were prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) and include the assets, liabilities, revenues and expenses of all controlled subsidiaries. The condensed consolidated statements of operations include the results of entities acquired from the date of each respective acquisition. Interests held by third parties in consolidated subsidiaries are presented as non-controlling interests, which represents the non-controlling stockholders’ interests in the underlying net assets of the Company’s consolidated subsidiaries. For entities where the Company does not have a controlling interest (financial or operating), the investments in such entities are accounted for using the equity method. The Company applies the equity method of accounting when it has the ability to exercise significant influence over the operating and financial policies of an investee. The Company measures all other investments at fair value with changes in fair value recognized in net income or in the case that an equity investment does not have readily determinable fair values, at cost minus impairment (if any) plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment. The unaudited interim condensed consolidated financial statements and related disclosures have been prepared by management on a basis consistent with the annual consolidated financial statements and, in the opinion of management, include all adjustments necessary for a fair statement of the interim periods presented. The results of the interim periods presented are not necessarily indicative of the results expected for the full year. Certain information and notes normally included in financial statements prepared in accordance with GAAP have been condensed or omitted under the SEC’s rules and regulations. Accordingly, the unaudited condensed consolidated financial statements and notes included herein should be read in conjunction with the Company’s audited consolidated financial statements and the related notes for the year ended December 31, 2023 included in the 2023 Form 10-K.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make judgments, estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and reported amounts of revenue and expenses during the reporting periods covered by the condensed consolidated financial statements and accompanying notes. These judgments, estimates and assumptions are used for, but not limited to (i) valuation of the Company’s common stock and stock awards, (ii) fair value of acquired intangible assets and goodwill, (iii) fair value of contingent consideration arrangements in connection with business combinations, (iv) incremental borrowing rate used for the Company’s operating leases, (v) useful lives of long-lived assets, (vi) impairment of intangible assets and goodwill, (vii) allowance for Compass Concierge receivables and (viii) income taxes and certain deferred tax assets. The Company determines its estimates and judgments based on historical experience and on various other assumptions that it believes are reasonable under the circumstances. However, actual results could differ from these estimates and these differences may be material.
Business Combinations	Business Combinations
Stock-Based Compensation	Stock-Based Compensation The Company measures compensation expense for all stock-based awards based on the estimated fair value of the awards on the date of grant. Compensation expense is generally recognized as expense on a straight-line basis over the service period based on the vesting requirements generally ranging from one For stock options, which the Company issues to employees, affiliated agents and in certain cases in connection with business combinations, the Company generally estimates the fair value using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including (1) the fair value of common stock, (2) the expected stock price volatility, (3) the expected term of the award, (4) the risk-free interest rate and (5) expected dividends. The Company also issues RSUs to employees, and to affiliated agents and in certain cases in connection with business combinations. In addition to the issuance of RSUs to agents as equity compensation for the provision of services, the Company previously offered RSUs to affiliated agents through its Agent Equity Program. The Agent Equity Program offered affiliated agents the ability to elect to have a portion of their commissions earned during a calendar year to be paid in the form of RSUs. RSUs issued in connection with the Agent Equity Program were granted at the beginning of the year following the calendar year in which the commissions were earned and are subject to the terms and conditions of the 2012 Stock Incentive Plan and the 2021 Equity Incentive Plan, as applicable. The Company discontinued the Agent Equity Program following the issuance of RSUs during the first quarter of 2023 related to the 2022 Agent Equity Program. For RSUs granted in connection with the 2022 Agent Equity Program the Company determined the value of the stock-based compensation expense at the time the underlying commission was earned and recognized the associated expense on a straight-line basis over the requisite service periods beginning on the closing date of the underlying real estate commission transactions. The stock-based compensation expense was recorded as a liability throughout the service periods and was reclassified to Additional paid-in capital at the end of the vesting period when the underlying RSUs were issued. On a limited basis, the Company has issued stock options and RSUs that contain service, performance and market-based vesting conditions. Such awards were valued using a Monte Carlo simulation and the underlying expense will be recognized as the associated vesting conditions are met.
New Accounting Pronouncements	New Accounting Pronouncements In December 2023, the FASB issued ASU 2023-09, Income Taxes - Improvements to Income Tax Disclosures . This standard includes enhanced income tax disclosures primarily related to the effective tax rate reconciliation and income taxes paid for annual periods. The amendments in this update are effective for public companies with fiscal years beginning after December 15, 2024, with early adoption permitted. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures , which is intended to improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant expenses. The update will require public entities to disclose significant segment expenses that are regularly provided to the chief operating decision maker and included within segment profit and loss. The amendments are effective for the Company's annual periods beginning January 1, 2024, and interim periods beginning January 1, 2025, with early adoption permitted, and will be applied retrospectively to all prior periods presented in the financial statements. We are currently evaluating the impact of the adoption of this standard to determine its impact on the Company's disclosures.

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Summary of Changes in Contingent Consideration Measured at Fair Value on a Recurring Basis	Changes in contingent consideration measured at fair value on a recurring basis were as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Opening balance $ 26.9 $ 17.6 $ 20.9 $ 14.0 Acquisitions and measurement period adjustments (0.3) 4.0 7.1 12.8 Payments (0.4) (3.3) (2.7) (9.1) Changes in fair value included in net loss 0.4 0.5 1.3 1.1 Closing balance $ 26.6 $ 18.8 $ 26.6 $ 18.8

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Summary of Fair Value Measurements of Our Financial Instruments	The following table presents the balances of contingent consideration as presented in the condensed consolidated balance sheets (in millions): September 30, 2024 December 31, 2023 Accrued expenses and other current liabilities $ 3.1 $ 4.5 Other non-current liabilities 23.5 16.4 Total contingent consideration $ 26.6 $ 20.9

Preferred Stock and Common St_2

Preferred Stock and Common Stock (Tables)	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Summary of Stock by Class	The following tables reflect the authorized, issued and outstanding shares for each of the classes of common stock as of September 30, 2024 and December 31, 2023: September 30, 2024 Shares Shares Shares Class A common stock 12,500,000,000 491,822,267 491,822,267 Class B common stock 1,250,000,000 — — Class C common stock 100,000,000 15,758,787 15,758,787 Total 13,850,000,000 507,581,054 507,581,054 December 31, 2023 Shares Shares Shares Class A common stock 12,500,000,000 465,633,122 465,633,122 Class B common stock 1,250,000,000 — — Class C common stock 100,000,000 19,260,144 19,260,144 Total 13,850,000,000 484,893,266 484,893,266

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Stock Option Activity	A summary of stock option activity under the 2012 Plan and the 2021 Plan, including 1.1 million stock options that were granted outside of the 2012 Plan in 2019, is presented below (in millions, except share and per share amounts): Number of Weighted Average Weighted Average Aggregate Intrinsic Value (1) Balance as of December 31, 2023 40,527,848 $ 5.60 5.1 $ 20.2 Granted — — Exercised (3,258,748) 1.83 Forfeited (1,904,614) 6.62 Balance as of September 30, 2024 35,364,486 $ 5.89 4.6 $ 38.8 Exercisable and vested at September 30, 2024 32,751,775 $ 5.64 4.5 $ 38.3 (1)
Summary of Restricted Stock Units Activity	A summary of RSU activity under the 2012 Plan and the 2021 Plan is presented below: Number of Awards Weighted Average Grant Date Fair Value Balance as of December 31, 2023 29,943,818 $ 5.15 Granted 24,238,196 3.62 Vested and converted to common stock (1) (18,204,182) 4.35 Forfeited (3,111,621) 4.61 Balance as of September 30, 2024 32,866,211 $ 4.52 (1) During the nine months ended September 30, 2024, the Company net settled all RSUs through which it issued an aggregate of 18.2 million shares of Class A common stock and withheld an aggregate of 6.1 million shares of Class A common st ock to satisfy $21.8 million of tax withholding obligations on behalf of the Company’s employees.
Summary of Share-based Payment Arrangement, Expensed and Capitalized, Amount	Total stock-based compensation expense included in the condensed consolidated statements of operations for the three and nine months ended September 30, 2024 and 2023 is as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Commissions and other related expense $ — $ — $ — $ 11.6 Sales and marketing 7.8 8.8 24.0 26.4 Operations and support 4.2 4.5 12.3 11.6 Research and development 14.6 11.4 44.7 34.4 General and administrative 5.9 13.3 15.3 37.9 Total stock-based compensation expense $ 32.5 $ 38.0 $ 96.3 $ 121.9

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Compass, Inc. (Tables)	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders	The following table sets forth the computation of basic and diluted net loss per share attributable to Compass, Inc. (in millions, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Numerator: Net loss attributable to Compass, Inc. $ (1.7) $ (39.4) $ (113.9) $ (237.6) Denominator: Weighted-average shares used in computing net loss per share attributable to Compass, Inc., basic and diluted 505,993,014 470,945,736 498,247,783 460,730,792 Net loss per share attributable to Compass, Inc., basic and diluted $ (0.00) $ (0.08) $ (0.23) $ (0.52)
Summary of Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following participating securities were excluded from the computation of diluted net loss per share attributable to Compass, Inc. for the periods presented, because including them would have been anti-dilutive (on an as-converted basis): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Outstanding stock options 35,364,486 41,439,848 35,364,486 41,439,848 Outstanding RSUs 32,866,211 48,481,527 32,866,211 48,481,527 Shares subject to the Employee Stock Purchase Plan 336,429 685,943 336,429 685,943 Unvested early exercised stock options 1,660 29,070 1,660 29,070 Unvested common stock 115,895 — 115,895 — Contingent common stock to be issued in connection with the Strategic Transaction — 1,791,802 — 1,791,802 Total 68,684,681 92,428,190 68,684,681 92,428,190

Compass Concierge Receivables_2

Compass Concierge Receivables and Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2024
Receivables [Abstract]
Summary of ACL for Concierge Receivables	The following table summarizes the activity of the ACL for Concierge Receivables for the three and nine months ended September 30, 2024 (in millions): Three Months Ended September 30, 2024 Nine Months Ended September 30, 2024 Beginning of period $ 11.1 $ 13.2 Allowances 0.1 0.3 Net write-offs (0.8) (3.1) End of period $ 10.4 $ 10.4
Summary of Aging Analysis of Concierge Receivables	The following table presents the aging analysis of Concierge Receivables as of September 30, 2024 (in millions): September 30, 2024 Current $ 40.7 31-90 days past due 1.4 Over 90 days past due 3.1 Total $ 45.2

Restructuring Activities (Table

Restructuring Activities (Tables)	9 Months Ended
	Sep. 30, 2024
Restructuring and Related Activities [Abstract]
Summary of restructuring costs	The following table summarizes the total costs incurred in connection with the Company's restructuring activities taken during the three and nine months ended September 30, 2024 and 2023 (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Severance related personnel costs $ — $ — $ — $ 8.9 Lease termination costs 1.7 1.7 7.5 18.8 Accelerated depreciation 0.1 — 1.9 5.3 Total expense $ 1.8 $ 1.7 $ 9.4 $ 33.0 The total costs incurred in connection with the Company's restructuring activities taken during the three and nine months ended September 30, 2024 and 2023 were included in the condensed consolidated statements of operations as follows (in millions): Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 Restructuring costs $ 1.7 $ 1.7 $ 7.5 $ 27.7 Depreciation and amortization 0.1 — 1.9 5.3 Total expense $ 1.8 $ 1.7 $ 9.4 $ 33.0
Other Commitments	The following table summarizes the estimated timing of the Company's future lease and lease-related payments, net of amounts contractually subleased, related to restructuring activities as of September 30, 2024 (in millions): Payment Due by Period Remaining 2024 $ 5.5 2025 11.4 2026 7.0 2027 5.7 Thereafter 7.7 Total $ 37.3

Business and Basis of Present_2

Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Business [Line Items]
Date of incorporation	Oct. 04, 2012
Cash and cash equivalents	$ 211.2	$ 166.9
Revolving credit facility
Business [Line Items]
Line of credit facility, available borrowing capacity	$ 295.1

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - RSUs	1 Months Ended
	Dec. 31, 2020
Minimum
Accounting Policies [Line Items]
Share based compensation by share based payment arrangement service based vesting period	1 year
Maximum
Accounting Policies [Line Items]
Share based compensation by share based payment arrangement service based vesting period	5 years

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($) vote	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2024 USD ($)	Mar. 31, 2024	Dec. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Business Acquisition [Line Items]
Payment to acquire business, net of cash acquired				$ 18.9	$ (0.7)
Total contingent consideration	$ 26.6	$ 26.9	$ 18.8	26.6	18.8			$ 20.9	$ 17.6	$ 14
Goodwill	234.1			234.1				$ 209.8
Contingent liabilities undiscounted maximum payment	39.7			39.7
Future consideration to be paid to the acquirees	2.6			2.6
Compensation expenses, future services	0		$ 0.1	0	$ 2.1
Residential Real Estate Brokerages, Title Insurance And Escrow Settlement Services Company
Business Acquisition [Line Items]
Equity interest issued or issuable				26.1
Payment to acquire business, net of cash acquired				21.3
Deferred cash payment	2.7			2.7
Total contingent consideration	7.1			7.1
Recognized identifiable assets and liabilities assumed, other assets	20.1			20.1
Recognized identifiable assets and liabilities assumed, other liabilities	18.9			18.9
Goodwill	24.9			24.9
Goodwill, expected tax deductible amount	$ 9.8			$ 9.8
Residential Real Estate Brokerages, Title Insurance And Escrow Settlement Services Company | Minimum
Business Acquisition [Line Items]
Useful life (in years)	5 years			5 years
Residential Real Estate Brokerages, Title Insurance And Escrow Settlement Services Company | Maximum
Business Acquisition [Line Items]
Useful life (in years)	6 years			6 years
Residential Real Estate Brokerages, Title Insurance And Escrow Settlement Services Company | Forecast
Business Acquisition [Line Items]
Goodwill, expected tax deductible amount						$ 17
Residential Real Estate Brokerages, Title Insurance And Escrow Settlement Services Company | Customer Relationships
Business Acquisition [Line Items]
Recognized identifiable assets and liabilities assumed, intangible assets, other than goodwill	$ 28.7			$ 28.7
Residential Real Estate Brokerages, Title Insurance And Escrow Settlement Services Company | Trademarks
Business Acquisition [Line Items]
Recognized identifiable assets and liabilities assumed, intangible assets, other than goodwill	$ 2.4			$ 2.4
Residential Real Estate Brokerages
Business Acquisition [Line Items]
Number of businesses acquired | vote		2
Title Insurance And Escrow Settlement Services Company
Business Acquisition [Line Items]
Ownership interest acquired (in percent)							100%
Latter & Blum Holdings, LLC
Business Acquisition [Line Items]
Ownership interest acquired (in percent)		100%
Parks Village Nashville, LLC
Business Acquisition [Line Items]
Ownership interest acquired (in percent)		100%

Acquisitions - Summary of Chang

Acquisitions - Summary of Changes in Contingent Consideration Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes In Contingent Consideration Measured At Fair Value On A Recurring Basis [Roll Forward]
Opening balance	$ 26.9	$ 17.6	$ 20.9	$ 14
Acquisitions and measurement period adjustments	(0.3)	4	7.1	12.8
Payments	(0.4)	(3.3)	(2.7)	(9.1)
Changes in fair value included in net loss	0.4	0.5	1.3	1.1
Closing balance	$ 26.6	$ 18.8	$ 26.6	$ 18.8

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent consideration fair value disclosure	$ 26.6	$ 20.9
Cash And Money Market Funds | Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash Equivalents, fair value disclosure	$ 211.2	$ 166.9

Fair Value of Financial Asset_4

Fair Value of Financial Assets and Liabilities - Balances of Contingent Consideration (Detail) - USD ($) $ in Millions	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Accrued expenses and other current liabilities	$ 3.1		$ 4.5
Other non-current liabilities	23.5		16.4
Total contingent consideration	$ 26.6	$ 26.9	$ 20.9	$ 18.8	$ 17.6	$ 14

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Millions		9 Months Ended
	Aug. 04, 2023	Sep. 30, 2024	Dec. 31, 2023	Mar. 31, 2021	Jul. 31, 2020
Debt [Line Items]
Letters of credit		$ 54.9	$ 44.4
Concierge credit facility
Debt [Line Items]
Maximum borrowing capacity					$ 75
Debt instrument interest rate (in percent)		8%
Concierge credit facility | Concierge Facility Used Greater Than Fifty Percent
Debt [Line Items]
Unused capacity commitment fee (in percent)	0.35%
Line of credit facility, unused capacity, commitment fee, threshold	50%
Concierge credit facility | Concierge Facility Used Less Than Fifty Percent
Debt [Line Items]
Unused capacity commitment fee (in percent)	0.50%
Line of credit facility, unused capacity, commitment fee, threshold	50%
Concierge credit facility | Secured Overnight Financing Rate (SOFR)
Debt [Line Items]
Debt instrument, basis spread on variable rate	2.75%
Revolving credit facility
Debt [Line Items]
Maximum borrowing capacity		$ 350		$ 350
Debt instrument, basis spread on variable rate		1%
Unused capacity commitment fee (in percent)		0.175%
Line of credit facility maximum borrowing capacity sublimit				$ 125
Outstanding borrowings		$ 0
Revolving credit facility | Minimum
Debt [Line Items]
Liquidity required by financial covenants		150
Revolving credit facility | Four Fiscal Quarters Of 2024 And Thereafter | Minimum
Debt [Line Items]
Required consolidated revenue threshold		$ 4,668
Revolving credit facility | Secured Overnight Financing Rate (SOFR)
Debt [Line Items]
Debt instrument, basis spread on variable rate		1.50%
Debt instrument, basis spread on variable rate, adjustment		0.10%
Revolving credit facility | Secured Overnight Financing Rate (SOFR) Term Rate
Debt [Line Items]
Debt instrument, basis spread on variable rate		1%
Revolving credit facility | Base Rate
Debt [Line Items]
Debt instrument, basis spread on variable rate		0.50%
Revolving credit facility | Fed Funds Effective Rate Overnight Index Swap Rate
Debt [Line Items]
Debt instrument, basis spread on variable rate		0.50%
Revolving credit facility | Debt Default Interest Rate
Debt [Line Items]
Debt instrument, basis spread on variable rate		2%
Letter of Credit
Debt [Line Items]
Letters of credit		$ 54.9

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions		3 Months Ended
	Mar. 21, 2024 USD ($)	Jun. 30, 2025	Jun. 30, 2024	Mar. 31, 2024 USD ($)	Sep. 30, 2024 USD ($) lawsuit	Dec. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Letters of credit					$ 54.9	$ 44.4
Escrow and trust deposits					$ 246.1	120
Antitrust Lawsuits
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party	$ 57.5			$ 57.5
Settlement amount paid			0.50
Antitrust Lawsuits | Forecast
Loss Contingencies [Line Items]
Settlement amount to be paid within one year		0.50
Putative Class Action Lawsuit
Loss Contingencies [Line Items]
Loss contingency, number of lawsuits | lawsuit					8
Individual Law Suit
Loss Contingencies [Line Items]
Loss contingency, number of lawsuits | lawsuit					1
Revolving credit facility
Loss Contingencies [Line Items]
Letters of credit					$ 54.9	43.8
Cash and Cash Equivalents
Loss Contingencies [Line Items]
Letters of credit						$ 0.6

Preferred Stock and Common St_3

Preferred Stock and Common Stock - Additional Information (Detail) $ / shares in Units, $ in Millions		1 Months Ended
	Feb. 28, 2021 vote	Aug. 31, 2023 USD ($) shares	Sep. 30, 2024 vote $ / shares shares	Dec. 31, 2023 $ / shares shares	Apr. 30, 2021 $ / shares shares
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)			0	0
Preferred stock shares outstanding (in shares)			0	0
Common stock shares authorized (in shares)			13,850,000,000	13,850,000,000
Common stock par or stated value per share (in dollars per share) | $ / shares			$ 0.00001	$ 0.00001
Strategic transaction, consideration received | $		$ 32.3
Strategic transaction, number of shares issued		9,000,000
Strategic transaction, contingent consideration, range of outcomes, value, high | $		$ 5.5
Common Class C
Class of Stock [Line Items]
Common Stock voting rights	Each share of Class C common stock is entitled to twenty votes
Common stock shares authorized (in shares)			100,000,000	100,000,000
Voting rights, number of votes for each share | vote			20
Number of votes per share of common stock | vote	20
Common Class A
Class of Stock [Line Items]
Common stock conversion ratio			1
Common stock shares authorized (in shares)			12,500,000,000	12,500,000,000
Voting rights, number of votes for each share | vote			1
Common Class B
Class of Stock [Line Items]
Common stock shares authorized (in shares)			1,250,000,000	1,250,000,000
Voting rights, number of votes for each share | vote			0
Restated Certificate Of Incorporation | Undesignated Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)					25,000,000
Preferred stock, par value (in dollars per share) | $ / shares					$ 0.00001
Restated Certificate Of Incorporation | Common Class C
Class of Stock [Line Items]
Common stock shares authorized (in shares)					100,000,000
Restated Certificate Of Incorporation | Common Class A
Class of Stock [Line Items]
Common stock shares authorized (in shares)					12,500,000,000
Restated Certificate Of Incorporation | Common Class B
Class of Stock [Line Items]
Common stock shares authorized (in shares)					1,250,000,000

Preferred Stock and Common St_4

Preferred Stock and Common Stock - Schedule of Stock by Class (Detail) - shares	Sep. 30, 2024	Dec. 31, 2023
Class of Stock [Line Items]
Shares authorized (in shares)	13,850,000,000	13,850,000,000
Shares issued (in shares)	507,581,054	484,893,266
Shares outstanding (in shares)	507,581,054	484,893,266
Class A common stock
Class of Stock [Line Items]
Shares authorized (in shares)	12,500,000,000	12,500,000,000
Shares issued (in shares)	491,822,267	465,633,122
Shares outstanding (in shares)	491,822,267	465,633,122
Class B common stock
Class of Stock [Line Items]
Shares authorized (in shares)	1,250,000,000	1,250,000,000
Shares issued (in shares)	0	0
Shares outstanding (in shares)	0	0
Class C common stock
Class of Stock [Line Items]
Shares authorized (in shares)	100,000,000	100,000,000
Shares issued (in shares)	15,758,787	19,260,144
Shares outstanding (in shares)	15,758,787	19,260,144

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	21 Months Ended
	Feb. 28, 2021	Jan. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2023	Jan. 01, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense			$ 32,500,000	$ 38,000,000	$ 96,300,000	$ 121,900,000
Intrinsic value of options					7,300,000	5,900,000
Unrecognized stock-based compensation expense			$ 138,000,000		$ 138,000,000
Unrecognized stock-based compensation, period of recognition					2 years
2021 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)	29,700,000		59,700,000		59,700,000
Number of additional shares available for grant (in shares)									24,200,000
2022 Agent Equity Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense						11,600,000	$ 41,700,000	$ 53,300,000
Outstanding stock options | 2012 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period					10 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					24,238,196
RSUs | Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued in period (in shares)					18,200,000
RSUs | 2012 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period					7 years
RSUs | 2022 Agent Equity Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred compensation share-based arrangements, liability		$ 53,300,000
RSUs | 2022 Agent Equity Program | Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		14,100,000
Employee Stock Purchase Plan | 2021 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in the shares authorized for issuance as a percentage of shares outstanding (in percent)	5%
Employee Stock Purchase Plan | 2021 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in the shares authorized for issuance as a percentage of shares outstanding (in percent)	1%
Number of additional shares available for grant (in shares)									4,700,000
Number of ESPP shares authorized (no more than) (in shares)	7,400,000
Purchase period	6 months
Purchase price of common stock, percent of market price (in percent)	85%
Stock based compensation expense			$ 200,000	$ 400,000	$ 700,000	$ 1,000,000
Employee withholdings for future purchases under the ESPP			$ 400,000		$ 400,000
Employee Stock Purchase Plan | 2021 Employee Stock Purchase Plan | Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)			18,100,000		18,100,000
Maximum employee subscription amount	$ 12,500
Shares issued in period (in shares)					700,000
Employee Stock Purchase Plan | 2021 Employee Stock Purchase Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of ESPP shares authorized (no more than) (in shares)	150,000,000

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023	Dec. 31, 2019
Number of Options
Balance, beginning of period (in shares)	40,527,848
Options granted (in shares)	0
Options exercised (in shares)	(3,258,748)
Options forfeited (in shares)	(1,904,614)
Balance, end of period (in shares)	35,364,486	40,527,848
Exercisable and vested at end of period (in shares)	32,751,775
Weighted Average Exercise Price
Balance, beginning of period (in dollars per share)	$ 5.60
Options granted (in dollars per share)	0
Options exercised (in dollars per share)	1.83
Options forfeited (in dollars per share)	6.62
Balance, end of period (in dollars per share)	5.89	$ 5.60
Exercisable and vested at end of period (in dollars per shares)	$ 5.64
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Balance, weighted-average remaining contractual life (in years)	4 years 7 months 6 days	5 years 1 month 6 days
Exercisable at end of period, weighted-average remaining contractual life (in years)	4 years 6 months
Balance, aggregate intrinsic value	$ 38.8	$ 20.2
Exercisable and vested at end of period, aggregate intrinsic value	$ 38.3
Closing stock price (in dollars per share)	$ 6,110,000	$ 3,760,000
Outside of 2012 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options early exercised (in shares)			1,100,000

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Restricted Stock Units Activity (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Weighted Average Grant Date Fair Value
Taxes paid related to net share settlement of equity	$ 21.8	$ 17.9
RSUs
Number of Awards
Balance as of the beginning of the period (in shares)	29,943,818
Granted (in shares)	24,238,196
Vested and converted to common stock (in shares)	(18,204,182)
Forfeited (in shares)	(3,111,621)
Balance as of the end of period (in shares)	32,866,211
Weighted Average Grant Date Fair Value
Balance as of the beginning of the period (in dollars per share)	$ 4.52		$ 5.15
Granted (in dollars per share)	3.62
Vested and converted to common stock (in dollars per share)	4.35
Forfeited (in dollars per share)	4.61
Balance as of the end of period (in dollars per share)	$ 4.52
Taxes paid related to net share settlement of equity	$ 21.8
Common Class A | RSUs
Weighted Average Grant Date Fair Value
Shares issued in period (in shares)	18,200,000
Shares withheld for tax withholding obligation (in shares)	6,100,000

Stock-Based Compensation - Shar

Stock-Based Compensation - Share-based Payment Arrangement, Expensed and Capitalized, Amount (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock based compensation expense	$ 32.5	$ 38	$ 96.3	$ 121.9
Commissions and other related expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock based compensation expense	0	0	0	11.6
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock based compensation expense	7.8	8.8	24	26.4
Operations and support
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock based compensation expense	4.2	4.5	12.3	11.6
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock based compensation expense	14.6	11.4	44.7	34.4
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock based compensation expense	$ 5.9	$ 13.3	$ 15.3	$ 37.9

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ (0.3)	$ (0.5)	$ (0.7)	$ (0.5)

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Compass, Inc. - Schedule of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net loss attributable to Compass, Inc.	$ (1.7)	$ (39.4)	$ (113.9)	$ (237.6)
Denominator:
Weighted-average shares used in computing net loss per share attributable to Compass, Inc., basic (in shares)	505,993,014	470,945,736	498,247,783	460,730,792
Weighted-average shares used to compute net loss per share attributable to Compass, Inc., diluted (in shares)	505,993,014	470,945,736	498,247,783	460,730,792
Net loss per share attributable to Compass, Inc., basic (in dollars per share)	$ 0	$ (0.08)	$ (0.23)	$ (0.52)
Net loss per share attributable to Compass, Inc., diluted (in dollars per share)	$ 0	$ (0.08)	$ (0.23)	$ (0.52)

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Compass, Inc. - Schedule of Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	68,684,681	92,428,190	68,684,681	92,428,190
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	35,364,486	41,439,848	35,364,486	41,439,848
Outstanding RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	32,866,211	48,481,527	32,866,211	48,481,527
Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	336,429	685,943	336,429	685,943
Unvested early exercised stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,660	29,070	1,660	29,070
Unvested common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	115,895	0	115,895	0
Contingent common stock to be issued in connection with the Strategic Transaction
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	1,791,802	0	1,791,802

Compass Concierge Receivables_3

Compass Concierge Receivables and Allowance for Credit Losses - Additional Information (Detail)	Sep. 30, 2024	Dec. 31, 2023
Receivables [Abstract]
Financing receivables related to unsold properties (in percent)	98%	97%

Compass Concierge Receivables_4

Compass Concierge Receivables and Allowance for Credit Losses - Summary of ACL for Concierge Receivables (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning of period	$ 11.1	$ 13.2
Allowances	0.1	0.3
Net write-offs	(0.8)	(3.1)
End of period	$ 10.4	$ 10.4

Compass Concierge Receivables_5

Compass Concierge Receivables and Allowance for Credit Losses - Summary of Aging Analysis of Concierge Receivables (Detail) $ in Millions	Sep. 30, 2024 USD ($)
Financing Receivable, Past Due [Line Items]
Concierge receivables	$ 45.2
Current
Financing Receivable, Past Due [Line Items]
Concierge receivables	40.7
31-90 days past due
Financing Receivable, Past Due [Line Items]
Concierge receivables	1.4
Over 90 days past due
Financing Receivable, Past Due [Line Items]
Concierge receivables	$ 3.1

Restructuring Activities - Tota

Restructuring Activities - Total Costs Incurred and Expected to be Incurred (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Restructuring Cost and Reserve [Line Items]
Incurred cost	$ 1.8	$ 1.7	$ 9.4	$ 33
Severance related personnel costs
Restructuring Cost and Reserve [Line Items]
Incurred cost	0	0	0	8.9
Lease termination costs
Restructuring Cost and Reserve [Line Items]
Incurred cost	1.7	1.7	7.5	18.8
Accelerated depreciation
Restructuring Cost and Reserve [Line Items]
Incurred cost	$ 0.1	$ 0	$ 1.9	$ 5.3

Restructuring Activities - To_2

Restructuring Activities - Total Costs Incurred in Connection to Restructuring Activities Included in Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Restructuring Cost and Reserve [Line Items]
Incurred cost	$ 1.8	$ 1.7	$ 9.4	$ 33
Restructuring costs
Restructuring Cost and Reserve [Line Items]
Incurred cost	1.7	1.7	7.5	27.7
Depreciation and amortization
Restructuring Cost and Reserve [Line Items]
Incurred cost	$ 0.1	$ 0	$ 1.9	$ 5.3

Restructuring Activities - Rema

Restructuring Activities - Remaining Liability For Lease Termination Costs (Details) - Lease termination costs $ in Millions	Sep. 30, 2024 USD ($)
Restructuring Cost and Reserve [Line Items]
Remaining 2024	$ 5.5
2025	11.4
2026	7
2027	5.7
Thereafter	7.7
Total	$ 37.3