Filed Pursuant to Rule 424(b)(3)
Registration No. 333-263798
PROSPECTUS SUPPLEMENT NO. 10
(To Prospectus dated
June 1, 2022)
UP TO 19,354,059 SHARES OF COMMON STOCK
ISSUABLE UPON EXERCISE OF WARRANTS
UP TO 96,941,181 SHARES OF COMMON STOCK
UP TO 4,450,000 WARRANTS TO PURCHASE COMMON STOCK
This prospectus supplement
supplements the prospectus, dated June 1, 2022 (the Prospectus), which forms a part of our registration statement on Form S-1 (No. 333-263798). This
prospectus supplement is being filed to update and supplement the information in the Prospectus with the information contained in our Current Report on Form 8-K filed with the Securities and Exchange
Commission on December 16, 2022 (the Current Report). Accordingly, we have attached the Current Report to this prospectus supplement.
The Prospectus and this prospectus supplement relate to the issuance by us of up to an aggregate of 19,354,059 shares of our common stock, $0.0001 par value
per share (the common stock) consisting of (i) 4,450,000 shares of common stock issuable upon the exercise of 4,450,000 warrants (the private placement warrants) originally issued in a private placement in connection with the
initial public offering (the IPO) of Supernova Partners Acquisition Company II, Ltd., a Cayman Islands exempted company (Supernova), by the holders thereof, (ii) 8,624,972 shares of common stock issuable upon the exercise of
8,624,972 warrants (the public warrants and, together with the private placement warrants, the warrants) originally issued in the IPO by holders thereof, and (iii) 6,279,087 shares of common stock issuable upon the exercise
of warrants assumed by us and converted into warrants to purchase common stock (the Rigetti assumed warrants) in connection with the Business Combination (as defined below). We will receive the proceeds from the exercise of any warrants
and any Rigetti assumed warrants for cash.
The Prospectus and this prospectus supplement also relate to the offer and sale from time to time by the
selling securityholders named in this prospectus or their permitted transferees (the selling securityholders) of up to (i) 96,941,181 shares of common stock consisting of (a) 10,251,000 shares of common stock purchased by subscribers at
a price of $10.00 per share and 4,390,244 shares of common stock purchased by subscribers at a price of $10.25 per share in private placements pursuant to separate subscription agreements, (b) 8,625,000 shares of common stock (the Founder
Shares) originally purchased by Supernova Partners II LLC (Supernova Sponsor) for $25,000, or for approximately $0.004 per share, in a private placement in connection with the IPO, including 3,059,273 Founder Shares subject to
vesting and forfeiture (the Sponsor Vesting Shares), (c) 4,450,000 shares of common stock issuable upon exercise of the private placement warrants, (d) 2,446,716 shares of common stock issuable pursuant to the exercise of Rigetti assumed
warrants, which Rigetti assumed warrants have a weighted average exercise price of $0.6628 per share, (e) 6,226,065 shares of common stock issuable upon exercise of outstanding options, which have an exercise price of $0.272 per share, (f) 6,288,369
shares of common stock issuable in connection with the vesting and settlement of outstanding restricted stock units, which were assumed by and converted into restricted stock awards for common stock in connection with the Business Combination based
on an acquiror share value of $10.00 per share and (g) 54,263,787 shares of common stock issued in connection with the Business Combination as merger consideration at an acquiror share value of $10.00 per share, and (ii) up to 4,450,000 private
placement warrants, which were purchased by Supernova Sponsor at a price of $2.00 per warrant. We will not receive any proceeds from the sale of shares of common stock or warrants by the selling securityholders pursuant to this prospectus.