Gossamer Bio sets 1-for-80 reverse stock split
Gossamer Bio will execute a 1-for-80 reverse split and sharply cut authorized shares to support continued Nasdaq Global Select Market listing.
Rhea-AI Filing Summary
Gossamer Bio, Inc. (GOSS) is implementing a 1-for-80 reverse stock split of its common stock, together with a proportionate reduction in authorized shares of common and total capital stock. The reverse split and authorized share reduction are expected to become effective on September 10, 2026 at 11:59 p.m. Eastern Time, with split-adjusted trading on the Nasdaq Global Select Market beginning September 11, 2026 under the same ticker GOSS and a new CUSIP. The reverse split is intended to help the company regain compliance with Nasdaq’s minimum bid price requirement, while leaving each stockholder’s percentage ownership and voting power essentially unchanged apart from minor rounding adjustments for fractional shares.
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Filing Explained
The 1-for-80 split is scheduled for September 10, with authorized common shares falling to 50 million and outstanding instruments adjusted proportionately.
The September 9 8-K places the selected 1-for-80 reverse stock split in an expected implementation state: at effectiveness, each 80 shares becomes one, while authorized common shares fall from
A reverse stock split consolidates shares and proportionately raises the per-share price; the company says each holder’s percentage ownership and proportional voting power will remain unchanged except for fractional-share treatment. Fractions will be rounded up to whole shares, including at the DTC participant level, although brokers and nominees may use their own processing procedures.
When effective, conversion rates for the outstanding convertible notes, shares and exercise prices for warrants and prefunded warrants, and shares and exercise prices for equity awards will be adjusted proportionately; shares reserved for future equity-plan issuance will also be reduced proportionately.
The filing states that the split is intended to help regain Nasdaq minimum-bid-price compliance, not that compliance has already been regained. Effectiveness is expected at 11:59 p.m. Eastern Time on
8-K Event Classification
2 items: 8.01, 9.01
2 items
Item 8.01
Other Events
Other
Voluntary disclosure of events the company deems important to shareholders but not covered by other items.
Item 9.01
Financial Statements and Exhibits
Exhibits
Financial statements, pro forma financial information, or exhibit attachments filed with this report.
Key Figures
Reverse stock split ratio: 1-for-80
Effective date and time: September 10, 2026, 11:59 p.m. Eastern Time
Split-adjusted trading start date: September 11, 2026
+4 more
7 metrics
Reverse stock split ratio
1-for-80
Every 80 shares of common stock will be combined into 1 share at the effective time
Effective date and time
September 10, 2026, 11:59 p.m. Eastern Time
Planned effectiveness of the reverse stock split and authorized share reduction
Split-adjusted trading start date
September 11, 2026
Shares expected to begin trading on a split-adjusted basis on Nasdaq Global Select Market
Authorized common stock before reduction
4,000,000,000 shares
Authorized common shares prior to the authorized share reduction
Authorized common stock after reduction
50,000,000 shares
Authorized common shares following the authorized share reduction
Total authorized capital stock before reduction
4,070,000,000 shares
Total authorized capital stock prior to the authorized share reduction
Total authorized capital stock after reduction
120,000,000 shares
Total authorized capital stock following the authorized share reduction
Key Terms
reverse stock split, Authorized Share Reduction, convertible notes, equity incentive plans, +1 more
5 terms
reverse stock split financial
"approved thirty alternate amendments ... to effect a reverse stock split"
A reverse stock split reduces a company's number of outstanding shares while raising the price per share proportionally, so the total value of each investor's holding is unchanged; a 1-for-10 split turns 100 shares worth $1 each into 10 shares worth $10 each. Companies often do this to regain compliance with an exchange's minimum price rule or to attract investors who avoid very low-priced stocks.
convertible notes financial
"the conversion rates of the Company’s outstanding convertible notes ... will each be proportionately adjusted"
Convertible notes are a type of short-term loan that a company receives from investors, which can later be turned into company shares instead of being paid back in cash. They matter to investors because they offer a way to support a company early on while giving the potential to own a stake in its success if the company grows and later raises more funding.
equity incentive plans financial
"equity awards under the Company’s equity incentive plans ... will each be proportionately adjusted"
Equity incentive plans are company programs that pay employees, executives, or directors with company stock, stock options, or share units instead of or in addition to cash, aiming to align their interests with shareholders—like giving team members a stake in the house they help build. For investors this matters because such plans can motivate better company performance but also dilute existing ownership and increase reported compensation costs, so they affect future earnings, voting power, and share value.
minimum bid price requirement regulatory
"intended to help the Company regain compliance with the minimum bid price requirement"
A minimum bid price requirement is a rule that a stock must trade above a set price for a specified period to stay listed on an exchange. It matters to investors because falling below that threshold can trigger warnings or removal from the exchange, which can cut liquidity, reduce visibility, and often lead to sharper declines in share value—think of it like a venue’s minimum dress code that, if not met, can bar a performer from the stage.
FAQ
What reverse stock split did Gossamer Bio (GOSS) approve?
Gossamer Bio’s board selected a 1-for-80 reverse stock split of its common stock. Every 80 shares outstanding immediately before the effective time will be automatically reclassified into 1 share of common stock, with no cash paid in lieu of fractional shares.
When does the GOSS reverse stock split take effect and when will split-adjusted trading begin?
The reverse stock split and authorized share reduction are expected to become effective on September 10, 2026 at 11:59 p.m. Eastern Time. Split-adjusted trading on the Nasdaq Global Select Market is expected to begin at market open on September 11, 2026 under ticker GOSS.
Why is Gossamer Bio conducting a 1-for-80 reverse stock split?
The reverse stock split is intended to help regain compliance with the Nasdaq Global Select Market’s minimum bid price requirement for continued listing, by reducing the number of shares outstanding and thereby increasing the per-share trading price.
What happens to Gossamer Bio’s convertible notes, warrants, and equity awards after the reverse split?
Upon effectiveness, the conversion rates of outstanding convertible notes, the shares issuable and exercise prices of warrants and prefunded warrants, and the shares and exercise prices under equity incentive plans will each be proportionately adjusted to reflect the 1-for-80 reverse split. Plan reserve shares will also be proportionately reduced.
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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): September 9, 2026
(Exact name of Registrant as Specified in Its Charter)
| (State or Other Jurisdiction of Incorporation) | (Commission File Number) | (IRS Employer Identification No.) | ||||||
(Address of Principal Executive Offices) (Zip Code)
(858 ) 684-1300
(Registrant’s Telephone Number, Including Area Code)
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:
| Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) | |||||
| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) | |||||
| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) | |||||
| Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) | |||||
Securities registered pursuant to Section 12(b) of the Act:
| Title of each class | Trading Symbol(s) | Name of each exchange on which registered | ||||||||||||
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 8.01 Other Events.
As previously disclosed, on July 14, 2026, the stockholders of Gossamer Bio, Inc. (the “Company”) approved thirty alternate amendments to the Company’s Amended and Restated Certificate of Incorporation to effect a reverse stock split (the “Reverse Stock Split”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), at one of thirty reverse stock split ratios, with the exact ratio to be determined by the board of directors of the Company (the “Board”), and a proportionate reduction in the number of authorized shares of Common Stock (and a corresponding decrease in the total number of authorized shares of capital stock) (the “Authorized Share Reduction”). On September 9, 2026, the Company announced that the Board has selected a 1-for-80 reverse stock split ratio. The Reverse Stock Split and Authorized Share Reduction are expected to become effective on September 10, 2026, at 11:59 p.m. Eastern Time (the “Effective Time”). Shares of Common Stock are expected to begin trading on a split-adjusted basis on the Nasdaq Global Select Market at market open on September 11, 2026 under the existing trading symbol “GOSS” and a new CUSIP number of 38341P 201. The Reverse Stock Split is intended to help the Company regain compliance with the minimum bid price requirement for continued listing on the Nasdaq Global Select Market.
In connection with the Reverse Stock Split, every 80 shares of Common Stock issued and outstanding immediately prior to the Effective Time will be automatically reclassified and combined into 1 share of Common Stock. No fractional shares of Common Stock will be issued as a result of the Reverse Stock Split. Instead, the Company will issue to holders of record who are entitled to a fraction of a share as a result of the Reverse Stock Split, a fraction of a share of Common Stock as is necessary to round up to the nearest whole share. For shares held through The Depository Trust Company ("DTC"), fractions of shares will be issued as is necessary to round up to the nearest whole share at the DTC participant level. Brokers, banks or other nominees holding shares in "street name" will be instructed to effect the Reverse Stock Split for their beneficial holders; however, such brokers, banks or other nominees may apply their own specific procedures for processing the Reverse Stock Split.
Upon the effectiveness of the Reverse Stock Split, the conversion rates of the Company’s outstanding convertible notes (including the 5.00% Convertible Senior Notes due 2027 and the 7.50% Convertible Senior Secured First Lien Notes due 2030), the number of shares of Common Stock issuable upon exercise of outstanding warrants and prefunded warrants and the exercise prices thereof, and the number of shares subject to outstanding equity awards under the Company’s equity incentive plans (and the applicable exercise prices thereof), will each be proportionately adjusted pursuant to their respective terms and as determined by the Board to reflect the 1-for-80 reverse stock split ratio. In addition, the number of shares reserved for future issuance under the Company's equity incentive plans will be proportionately reduced.
In connection with the Authorized Share Reduction, the number of authorized shares of Common Stock will be reduced from 4,000,000,000 to 50,000,000, and the total number of authorized shares of capital stock will be correspondingly reduced from 4,070,000,000 to 120,000,000.
A copy of the press release announcing the Reverse Stock Split and Authorized Share Reduction is attached hereto as Exhibit 99.1 and is incorporated herein by reference.
* * *
Note Regarding Forward-Looking Statements.
The Company cautions you that statements contained in this report regarding matters that are not historical facts are forward-looking statements. These statements are based on the Company’s current beliefs and expectations. Such forward-looking statements include, but are not limited to, statements regarding: the expected timing and effectiveness of the Reverse Stock Split and Authorized Share Reduction, the anticipated adjustments to the Company’s outstanding convertible notes, warrants, prefunded warrants and equity awards, the anticipated impact of the Reverse Stock Split on the Company’s ability to regain compliance with the Nasdaq minimum bid price requirement and the other effects of the reverse stock split, including the expected issuance of additional fractional shares of common stock as is necessary to round up to the nearest whole share. The inclusion of forward-looking statements should not be regarded as a representation by Gossamer that any of its plans will be
achieved. Actual results may differ from those set forth in this report due to the risks and uncertainties inherent in Gossamer’s business, including, without limitation: the Reverse Stock Split may not result in a sustained increase in the price of the Company’s Common Stock and may not satisfy the Nasdaq minimum bid price requirement; any delay in the planned reverse stock split; the reverse stock split may impact our results of operations, business operations and reputation as well as the trading prices and volatility of the common stock; unstable market and economic conditions and changes in healthcare legislation, tariffs and trade policies may adversely affect the Company’s business and financial condition and the broader economy and biotechnology industry; and other risks described in the Company’s filings with the Securities and Exchange Commission (“SEC”), including under the heading “Risk Factors” in the Company’s annual report on Form 10-K and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Gossamer undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.
Item 9.01 Financial Statements and Exhibits.
(d) Exhibits.
Exhibit Number | Description | |||||||
| 99.1 | Press release issued by Gossamer Bio, Inc., dated September 9, 2026 | |||||||
| 104 | Cover page interactive data file (embedded with the inline XBRL document) | |||||||
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.
| GOSSAMER BIO, INC. | |||||||||||
| Date: September 9, 2026 | By: | /s/ Bryan Giraudo | |||||||||
| Bryan Giraudo | |||||||||||
| Chief Financial Officer and Chief Operating Officer | |||||||||||
Exhibit 99.1
Gossamer Bio Announces 1-for-80 Reverse Stock Split
September 9, 2026
SAN DIEGO—(BUSINESS WIRE)— September 9, 2026 — Gossamer Bio, Inc. (Nasdaq: GOSS) (the “Company” or “Gossamer”), a clinical-stage biopharmaceutical company focused on the development and commercialization of seralutinib for the treatment of pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease, today announced that its board of directors (the “Board”) has selected a 1-for-80 reverse stock split of the Company’s common stock and a proportionate reduction in the number of authorized shares of common stock (and a corresponding decrease in the total number of authorized shares of capital stock). At a special meeting held on July 14, 2026, the Company’s stockholders approved thirty alternate amendments to the Company’s amended and restated certificate of incorporation to effect a reverse stock split at one of thirty reverse stock split ratios, with the exact ratio to be determined by the Board.
The reverse stock split is intended to help the Company regain compliance with the minimum bid price requirement for continued listing on the Nasdaq Global Select Market.
The reverse stock split is expected to become effective at 11:59 p.m. Eastern Time on September 10, 2026. Shares of the Company’s common stock are expected to begin trading on a split-adjusted basis on the Nasdaq Global Select Market at market open on September 11, 2026 under the existing trading symbol “GOSS” and a new CUSIP number of 38341P 201.
In connection with the reverse stock split, every 80 shares of the Company’s common stock issued and outstanding immediately prior to the effective time will be automatically reclassified and combined into 1 share of common stock.
No fractional shares of common stock will be issued as a result of the reverse stock split. Instead, the Company will issue to holders of record who are entitled to a fraction of a share as a result of the Reverse Stock Split, a fraction of a share of common stock as is necessary to round up to the nearest whole share. For shares held through The Depository Trust Company ("DTC"), fractions of shares will be issued as is necessary to round up to the nearest whole share at the DTC participant level. Brokers, banks or other nominees holding shares in "street name" will be instructed to effect the reverse stock split for their
beneficial holders; however, such brokers, banks or other nominees may apply their own specific procedures for processing the reverse stock split.
In connection with the authorized share reduction, the number of authorized shares of common stock will be reduced from 4,000,000,000 to 50,000,000, and the total number of authorized shares of capital stock will be correspondingly reduced from 4,070,000,000 to 120,000,000.
Upon the effectiveness of the reverse stock split, the conversion rates of the Company’s outstanding convertible notes, the number of shares of common stock issuable upon exercise of outstanding warrants and prefunded warrants and the exercise prices thereof, and the number of shares subject to outstanding equity awards under the Company’s equity incentive plans (and the applicable exercise prices thereof), will each be proportionately adjusted pursuant to their respective terms and as determined by the Board to reflect the 1-for-80 reverse stock split ratio. In addition, the number of shares reserved for future issuance under the Company’s equity incentive plans will be proportionately reduced.
The reverse stock split has no effect on the par value of the Company’s common stock. Immediately after the reverse stock split, each stockholder’s percentage ownership interest in the Company and proportional voting power will remain unchanged, except for minor changes that will result from the treatment of fractional shares.
Computershare Trust Company, N.A. is acting as the transfer agent and, along with its affiliate Computershare, Inc., the exchange agent for the reverse stock split. Stockholders who hold registered shares in book-entry form at Computershare Trust Company, N.A. are not required to take any action to receive split-adjusted shares. Stockholders who hold shares through a broker, bank or other nominee will have their positions automatically adjusted and are not required to take any action.
Additional information about the reverse stock split can be found in the Company’s definitive proxy statement filed with the Securities and Exchange Commission (the “SEC”) on June 9, 2026, which is available free of charge at the SEC’s website, www.sec.gov, and on the Company’s website at https://www.gossamerbio.com/.
About Gossamer Bio
Gossamer Bio is a clinical-stage biopharmaceutical company focused on the development and commercialization of seralutinib for the treatment of pulmonary arterial hypertension and pulmonary
hypertension associated with interstitial lung disease. Its goal is to be an industry leader in, and to enhance the lives of patients living with, pulmonary hypertension.
Forward-Looking Statements
Gossamer cautions you that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. These statements are based on the Company’s current beliefs and expectations. Such forward-looking statements include, but are not limited to, statements regarding: the expected timing and effectiveness of the reverse stock split and authorized share reduction, the anticipated adjustments to the Company’s outstanding convertible notes, warrants, prefunded warrants and equity awards, the anticipated impact of the reverse stock split on the Company’s ability to regain compliance with the Nasdaq minimum bid price requirement and the other effects of the reverse stock split, including the expected issuance of additional fractional shares of common stock as is necessary to round up to the nearest whole share. The inclusion of forward-looking statements should not be regarded as a representation by Gossamer that any of its plans will be achieved. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in Gossamer’s business, including, without limitation: the reverse stock split may not result in a sustained increase in the price of the Company’s common stock and may not satisfy the Nasdaq minimum bid price requirement; any delay in the planned reverse stock split; the reverse stock split may impact our results of operations, business operations and reputation as well as the trading prices and volatility of the common stock; unstable market and economic conditions and changes in healthcare legislation, tariffs and trade policies may adversely affect the Company’s business and financial condition and the broader economy and biotechnology industry; and other risks described in the Company’s prior press releases and the Company’s filings with the SEC, including under the heading “Risk Factors” in the Company’s annual report on Form 10-K and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Gossamer undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.
For Investors and Media:
Bryan Giraudo, Chief Financial Officer & Chief Operating Officer
Gossamer Bio Investor Relations
ir@gossamerbio.com