UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): May 30, 2025

SONNET BIOTHERAPEUTICS HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (609) 375-2227

N/A

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

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 13(a) of the Exchange Act. ☐

Item 3.01. Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing.

On May 30, 2025, Sonnet BioTherapeutics Holdings, Inc. (the “Company”) received notice (the “Notice”) from The Nasdaq Stock Market LLC (“Nasdaq”) advising the Company that it is not in compliance with the minimum stockholders’ equity requirement for continued listing on The Nasdaq Capital Market. Nasdaq Listing Rule 5550(b)(1) requires companies listed on The Nasdaq Capital Market to maintain stockholders’ equity of at least $2,500,000 (the “Stockholders’ Equity Requirement”). In the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2025, the Company reported stockholders’ equity of $662,262, which is below the Stockholders’ Equity Requirement for continued listing. Additionally, as of May 30, 2025 and the date of this report, the Company does not meet the alternative Nasdaq compliance standards relating to the market value of listed securities of at least $35 million or net income of $500,000 from continuing operations in the most recently completed fiscal year, or in two of the last three most recently completed fiscal years.

The Notice has no immediate effect on the listing of the Company’s common stock and the Company’s common stock continues to trade on The Nasdaq Capital Market under the symbol “SONN,” subject to the Company’s compliance with the other continued listing requirements.

Pursuant to the Notice, Nasdaq has given the Company 45 calendar days, or until July 14, 2025, to submit to Nasdaq a plan to regain compliance. If our plan is accepted, Nasdaq may grant an extension of up to 180 calendar days from the date of the Notice to evidence compliance.

The Company is currently evaluating various courses of action to regain compliance and plans to timely submit its plan to Nasdaq to regain compliance with the Stockholders’ Equity Requirement. There can be no assurance that the Company’s plan will be accepted or that if it is, the Company will be able to regain compliance. If the Company’s plan to regain compliance is not accepted, or if it is and the Company does not regain compliance within 180 days from the date of Nasdaq’s letter, or if the Company fails to satisfy another Nasdaq requirement for continued listing, Nasdaq could provide notice that the Company’s common stock will become subject to delisting. In such event, Nasdaq rules permit the Company to appeal any delist determination. The hearing request would stay any suspension or delisting action pending the conclusion of the hearing process and the expiration of any additional extension period granted by the panel following the hearing.

Item 8.01 Other Events.

The Company is including the below update to its risk factors, for the purpose of supplementing and updating the disclosure contained in its Annual Report on Form 10-K for the fiscal year ended September 30, 2024, filed with the Securities and Exchange Commission (the “SEC”) on December 17, 2024, and its Quarterly Reports on Form 10-Q for the periods ended December 31, 2024 and March 31, 2025, filed with the SEC on February 13, 2025 and May 13, 2025, respectively.

Our failure to maintain compliance with Nasdaq’s continued listing requirements could result in the delisting of our common stock.

Our common stock is currently listed for trading on The Nasdaq Capital Market. We must satisfy the continued listing requirements of The Nasdaq Stock Market LLC (or Nasdaq) to maintain the listing of our common stock on The Nasdaq Capital Market.

On May 30, 2025, we received notice from the Listing Qualifications Staff (the “Staff”) of Nasdaq indicating that we were not in compliance with the $2.5 million minimum stockholders’ equity requirement for continued listing of our common stock on The Nasdaq Capital Market, as set forth in Nasdaq Listing Rule 5550(b)(1) (the “Minimum Stockholders’ Equity Rule”). In that regard, we reported stockholders’ equity of $662,262, as reported in the Company’s Quarterly Report on Form 10-Q for the period ended March 31, 2025 (we did not then, and do not now, meet the alternative compliance standards relating to the market value of listed securities of $35 million or net income from continuing operations of $500,000 in the most recently completed fiscal year or in two of the last three most recently completed fiscal years).

We intend to submit to Nasdaq, within the requisite time period, a plan to regain compliance with the Minimum Stockholders’ Equity Rule. There can be no assurance that Nasdaq will accept our plan or that we will be able to regain compliance with the Minimum Stockholders’ Equity Rule or maintain compliance with any other Nasdaq requirement in the future. In the event that we are unable to regain compliance with the Minimum Stockholders’ Equity Rule, our common stock may be delisted from The Nasdaq Capital Market.

If our common stock were delisted from The Nasdaq Capital Market, trading of our common stock would most likely take place on an over-the-counter market established for unlisted securities, such as the OTCQB or the Pink Market maintained by OTC Markets Group Inc. An investor would likely find it less convenient to sell, or to obtain accurate quotations in seeking to buy, our common stock on an over-the-counter market, and many investors would likely not buy or sell our common stock due to difficulty in accessing over-the-counter markets, policies preventing them from trading in securities not listed on a national exchange or other reasons. In addition, as a delisted security, our common stock would be subject to SEC rules as a “penny stock,” which impose additional disclosure requirements on broker-dealers. The regulations relating to penny stocks, coupled with the typically higher cost per trade to the investor of penny stocks due to factors such as broker commissions generally representing a higher percentage of the price of a penny stock than of a higher-priced stock, would further limit the ability of investors to trade in our common stock. Delisting would materially and adversely affect our ability to raise capital on terms acceptable to us, or at all, and may result in the potential loss of confidence by investors, suppliers, customers and employees and fewer business development opportunities. For these reasons and others, delisting would adversely affect the liquidity, trading volume and price of our common stock, causing the value of an investment in us to decrease and having an adverse effect on our business, financial condition and results of operations, including our ability to attract and retain qualified employees and to raise capital.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.