Filed Pursuant to Rule 424(b)(3)
Registration No. 333-266938
PROSPECTUS SUPPLEMENT NO. 9
(To Prospectus dated
September 14, 2022)
23,648,889 SHARES OF COMMON STOCK
This prospectus supplement supplements the prospectus, dated September 14, 2022 (the Prospectus), which forms a part of our
registration statement on Form S-1 (No. 333-266938). This prospectus supplement is being filed to update and supplement the information in the Prospectus with the
information contained in Item 2.05, Item 5.02 (including Exhibit 10.1 incorporated therein by reference) and Item 8.01 of our Current Report on Form 8-K filed with the Securities and Exchange
Commission on February 10, 2023 (the Current Report). Accordingly, we have attached the Current Report to this prospectus supplement.
The Prospectus and this prospectus supplement relate to the offer and resale of up to 23,648,889 shares of our common stock, $0.0001 per share
(the common stock), by B. Riley Principal Capital II, LLC (B. Riley or the selling stockholder). The shares included in the Prospectus consist of shares of common stock that we have issued or that we may, in our
discretion, elect to issue and sell to B. Riley, from time to time after the date of the Prospectus, pursuant to a Common Stock Purchase Agreement we entered into with B. Riley on August 11, 2022 (the Purchase Agreement), in which
B. Riley has committed to purchase from us, at our direction, up to $75,000,000 of our common stock, subject to terms and conditions specified in the Purchase Agreement. Concurrently with our execution of the Purchase Agreement on August 11,
2022, we issued 171,008 shares of common stock to B. Riley as consideration for its irrevocable commitment to purchase shares of our common stock at our election in our sole discretion, from time to time after the date of the Prospectus, upon the
terms and subject to the satisfaction of the conditions set forth in the Purchase Agreement. See the section of the Prospectus titled Committed Equity Financing for a description of the Purchase Agreement and the section titled
Selling Stockholder for additional information regarding the selling stockholder.
We are not selling any shares of common
stock being offered by the Prospectus and will not receive any of the proceeds from the sale of such shares by B. Riley. However, we may receive up to $75,000,000 in aggregate gross proceeds from sales of our common stock to B. Riley that we may, in
our discretion, elect to make, from time to time after the date of the Prospectus, pursuant to the Purchase Agreement.
B. Riley may sell
or otherwise dispose of the shares of common stock included in the Prospectus in a number of different ways and at varying prices. See the section of the Prospectus titled Plan of Distribution (Conflict of Interest) for more information
about how B. Riley may sell or otherwise dispose of the common stock being offered in the Prospectus. B. Riley is an underwriter within the meaning of Section 2(a)(11) of the Securities Act of 1933, as amended.
This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not be delivered or
utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectus supplement is qualified by reference to the Prospectus, including any amendments or supplements thereto, except to the extent that
the information in this prospectus supplement updates and supersedes the information contained therein.
The common stock is listed on The
Nasdaq Capital Market (Nasdaq) under the symbol RGTI. On February 9, 2023, the last reported sales price of the common stock as reported on Nasdaq was $1.06 per share.