QT IMAGING HOLDINGS, INC.

As filed with the U.S. Securities and Exchange Commission on January 16, 2025.

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

QT Imaging Holdings, Inc.

(Exact Name of Registrant as Specified in its Charter)

Dr. Raluca Dinu

Chief Executive Officer

3 Hamilton Landing, Suite 160,

Novato, CA 94949

Telephone: (650)276-7040

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Copies to:

Jeffrey C. Selman

DLA Piper LLP (US)

555 Mission Street, Suite 2400

San Francisco, California 94105

Tel: (415) 615-6035

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, please check the following box. x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 under the Securities Exchange Act of 1934:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. o

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission acting pursuant to said section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. Neither we nor the Selling Securityholders may sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

PRELIMINARY PROSPECTUS

SUBJECT TO COMPLETION-DATED JANUARY 16, 2025

8,807,116 Shares of Common Stock

This prospectus relates solely to the offer and sale from time to time of up to an aggregate 8,807,116 shares of the common stock, par value $0.0001 per share (the “Common Stock”), of QT Imaging Holdings, Inc. (the “Company,” “we,” “our” or “us”) by the selling securityholders identified in this prospectus (the “Selling Securityholders”). Such shares consist of (i) 4,383,558 shares of Common Stock (the “PIPE Shares”) that have been issued to certain of the Selling Securityholders who are “Purchasers” under a Securities Purchase Agreement, dated November 12, 2024 (the “Securities Purchase Agreement”) at a purchase price of $0.584 per share, (ii) 4,383,558 shares of Common Stock that are issuable upon the exercise of the Common Stock purchase warrant with a term of five years from the initial exercise date at an exercise price of $0.672 per share (the “PIPE Warrants”, and such shares issuable upon exercise of the PIPE Warrants, the “PIPE Warrant Shares”) acquired by the Purchasers, and (iii) 40,000 shares of Common Stock (the “ICR Shares”) issued to Interest Solutions, LLC (“Interest Solutions”), an affiliate of ICR, LLC (“ICR”) on December 13, 2024 pursuant to the terms of a Payment Agreement Regarding Consulting Services (the “Payment Agreement”) that we entered into with ICR on October 9, 2024, in which we agreed to partially pay ICR for consulting services to our predecessor, GigCapital5, Inc. (“GigCapital5”).

On November 22, 2024, the Company completed a private placement (the “Private Placement”), pursuant to the terms and conditions of the Securities Purchase Agreement by and between the Company and each of the Purchasers. Pursuant to the Securities Purchase Agreement, the Company entered into a Registration Rights Agreement with the Purchasers, dated November 12, 2024 (the “PIPE Registration Rights Agreement”). The aggregate gross proceeds to the Company from the Private Placement were approximately $2,560,000, before deducting offering expenses payable by the Company. See the section entitled “Private Placement of Shares of Common Stock and Warrants.”

The Company is registering the PIPE Shares and PIPE Warrant Shares for resale pursuant to the PIPE Registration Rights Agreement, and the ICR Shares purchase to the Payment Agreement. The Company will not receive any of the proceeds from the sale of these shares of the Common Stock by the Selling Securityholders. However, the Company will receive proceeds from the exercise of the PIPE Warrants, if the PIPE Warrants are exercised for cash. The Company intends to use those proceeds, if any, for general corporate purposes. All fees and expenses incident to the Company’s performance of or compliance with the PIPE Registration Rights Agreement will be borne by the Company, whether or not any PIPE Shares or PIPE Warrants are sold pursuant to a registration statement. The Selling Securityholders will pay any broker commissions or similar commissions or fees incurred for the sale of these shares of Common Stock.

The Selling Securityholders may offer such shares from time to time as it may determine through public or private transactions or through other means described in the section entitled “Plan of Distribution” beginning on page 202 of this prospectus, at prevailing market prices or at privately negotiated prices. This prospectus does not necessarily mean that the Selling Securityholders will offer or sell the shares. The Company cannot predict when or in what amounts the Selling Securityholders may sell any of the shares offered by this prospectus. Any shares of Common Stock subject to resale hereunder will have been issues by the Company and acquired by the Selling Securityholders prior to any resale of such shares pursuant to this prospectus.

Because all of the shares of Common Stock offered under this prospectus are being offered by the Selling Securityholders, the Company cannot currently determine the price or prices at which the Company’s shares may be sold under this prospectus.

Sales of a substantial number of shares of Common Stock in the public market, including the resale of the PIPE Shares, ICR Shares and PIPE Warrant Shares held by our stockholders pursuant to this prospectus or pursuant to Rule 144 promulgated under the Securities Act of 1933, as amended (“Rule 144”), could occur at any time. These sales, or the perception in the market that the holders of a large number of shares of Common Stock intend to sell shares, could reduce the market price of the Common Stock and make it more difficult for you to sell your holdings at times and prices that you determine are appropriate. Shares of Common Stock held by certain of our stockholders, including the Selling Securityholders, were purchased at an effective price lower than the current market price of our Common Stock. Accordingly, such stockholders could sell their securities at a per-share price that is less than the purchase price other stockholders paid and still realize a significant profit from the sale of those securities that could not be realized by our other stockholders. Furthermore, we expect that, because there is a large number of shares being registered pursuant to the registration statement of which this prospectus forms a part, the Selling Securityholders will continue to offer the securities covered thereby pursuant to this prospectus or pursuant to Rule 144 for a significant period of time, the precise duration of which cannot be predicted. Accordingly, the adverse market and price pressures resulting from an offering pursuant to the registration statement may continue for an extended period of time.

You should read this prospectus and any prospectus supplement of amendment carefully before you invest in our securities. Our Common Stock are listed on The Nasdaq Global Market (“Nasdaq”) under the symbol “QTI,” and our public warrants are traded in the over-the-counter (OTC) market under the symbol “QTIWW.” On , 2025, the closing price of our Common Stock was $[ ], and on , 2025, the closing price for our public warrants was $[ ].

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.

See the section entitled “Risk Factors” beginning on page 16 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 , 2025.

You should rely only on the information provided in this prospectus, as well as the information incorporated by reference into this prospectus and any applicable prospectus supplement. Neither we nor the Selling Securityholders have authorized anyone to provide you with different information. Neither we nor the Selling Securityholders are making an offer of these securities in any jurisdiction where the offer is not permitted. You should not assume that the information in this prospectus or any applicable prospectus supplement is accurate as of any date other than the date of the applicable document. Since the date of this prospectus and the documents incorporated by reference into this prospectus, our business, financial condition, results of operations and prospects may have changed.

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