Filed Pursuant to Rule 424(b)(3)
Registration No. 333-262201
PROSPECTUS
AdTheorent Holding Company, Inc.
Up to 76,713,193 Shares of Common Stock
Up to 15,973,904 Shares of Common Stock Issuable Upon the Exercise of Warrants
Up to 5,432,237 Warrants
This prospectus
relates to the issuance by us of up to an aggregate of 15,973,904 shares of our common stock, $0.0001 par value per share (Common Stock), which consists of (i) up to 10,541,667 shares of Common Stock issuable upon the exercise of
10,541,667 warrants (the Public Warrants) originally issued in the initial public offering of MCAP Acquisition Corporation, a Delaware corporation (MCAP), by the holders thereof, and (ii) up to 5,432,237 shares of Common
Stock issuable upon the exercise of 5,432,237 warrants (the Private Warrants and, together with the Public Warrants, the Warrants) originally issued in a private placement in connection with the initial public offering of
MCAP (551,096 of which are subject to escrow and forfeiture unless certain earn-out targets are achieved pursuant to the Business Combination Agreement (as defined below)). We will receive the proceeds from
any exercise of the Warrants for cash.
This prospectus also relates to the offer and sale from time to time, upon the expiration of lock-up agreements, if applicable, by (a) the selling stockholders named in this prospectus (including their permitted transferees, donees, pledgees and other successors-in-interest) (collectively, the Selling Stockholders) of up to 76,713,193 shares of Common Stock, consisting of (i) up to 12,150,000 shares of Common Stock, issued in a private
placement to the PIPE Investors (as defined below) pursuant to the terms of separate Subscription Agreements (as defined below) in connection with the Business Combination (as defined below), (ii) up to 5,432,237 shares of Common Stock that may
be issued upon the exercise of the Private Warrants, (iii) up to 7,906,250 shares of Common Stock held by MCAP Acquisition, LLC (the Sponsor) and its affiliates, (iv) up to 13,935,678 shares of Common Stock held by or
underlying equity awards held by affiliates of AdTheorent Holding Company, Inc. (AdTheorent or the Company), (v) up to 34,064,174 shares of Common Stock held by H.I.G. GrowthAdTheorent, LLC, and (vi) up to
3,224,854 additional shares of Common Stock held by entities affiliated with Monroe Capital, LLC and (b) the selling warrant holders named in this prospectus (including their permitted transferees, donees, pledgees and other successors-in-interest) (collectively, the Selling Warrantholders and, together with the Selling Stockholders, the Selling Securityholders) of up to
5,432,237 Private Warrants.
We are registering the securities for resale pursuant to the Selling Securityholders registration
rights under certain agreements between us and the Selling Securityholders. Our registration of the securities covered by this prospectus does not mean that the Selling Securityholders will offer or sell any of the shares of Common Stock or Warrants
registered hereby. The Selling Securityholders may offer, sell or distribute all or a portion of their shares of Common Stock or Warrants publicly or through private transactions at prevailing market prices or at negotiated prices. We provide more
information about how the Selling Securityholders may sell the shares or Warrants in the section entitled Plan of Distribution.
We are an emerging growth company as defined in Section 2(a) of the Securities Act of 1933, as amended (the Securities
Act), and are subject to reduced public company reporting requirements. This prospectus complies with the requirements that apply to an issuer that is an emerging growth company.
Our Common Stock and Public Warrants are listed on the Nasdaq Capital Market (the NASDAQ) under the symbols ADTH and
ADTHW, respectively. On January 28, 2022, the closing price of our Common Stock was $4.37 per share and the closing price of our Public Warrants was $0.56 per Warrant.
See the section entitled Risk Factors beginning on page 6 of this prospectus to read about factors
you should consider before buying our securities.
Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.
The date of this prospectus is January 31, 2022