Sinovac faces Nasdaq delisting over late 20-F

Sinovac Biotech Ltd. received a Nasdaq delisting determination on November 12, 2025 because it did not file its Form 20-F annual report for the year ended December 31, 2024 by the extended deadline of November 11, 2025.

Rhea-AI Filing Summary

Sinovac Biotech Ltd. received a Nasdaq delisting determination on November 12, 2025 because it did not file its Form 20-F annual report for the year ended December 31, 2024 by the extended deadline of November 11, 2025. The delay followed the April 2025 resignation of its prior auditor, Grant Thornton Zhitong Certified Public Accountants LLP.

The company has engaged UHY LLP as its new independent auditor and is working to complete the audit and file the 2024 Annual Report. Sinovac plans to request a hearing before a Nasdaq Hearing Panel by November 19, 2025, which will trigger an automatic 15-day stay of any trading suspension, and it will seek a further stay while it pursues regaining compliance with Nasdaq Listing Rule 5250(c)(1).

Positive

• None.

Negative

• Nasdaq delisting determination due to late 2024 Form 20-F – Nasdaq issued a staff determination to suspend and delist Sinovac’s securities after the company missed the extended November 11, 2025 deadline to file its 2024 Annual Report, citing non-compliance with Listing Rule 5250(c)(1).
• Prolonged financial reporting disruption after auditor resignation – The 2024 Annual Report delay follows the April 15, 2025 resignation of Grant Thornton Zhitong as auditor, extending the period during which investors lack updated audited financial statements.

Insights

Equity & Listing Standards Analyst

Nasdaq delisting risk arises from a late 2024 annual report, with appeal plans in motion.

Sinovac Biotech has received a Nasdaq staff determination to delist its shares after missing the extended deadline to file its Form 20-F for the year ended December 31, 2024. The filing delay stems from the April 2025 resignation of its former auditor, Grant Thornton Zhitong Certified Public Accountants LLP.

The company has since appointed UHY LLP as its independent registered public accounting firm and is working with them to complete the audit and file the 2024 Annual Report. The listing issue is tied specifically to non-compliance with Nasdaq Listing Rule 5250(c)(1), which requires timely filing of periodic financial reports.

Sinovac intends to request a hearing before a Nasdaq Hearing Panel by November 19, 2025. That request will automatically stay any suspension of trading for 15 days from the request date, and the company also plans to seek an additional stay during the hearing process. Outcomes will depend on completing the audit, filing the 2024 Annual Report, and the Hearing Panel’s decisions as described.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

Why did Sinovac Biotech (SVA) receive a Nasdaq delisting notice?

Sinovac received a Nasdaq delisting determination because it failed to file its Form 20-F annual report for the year ended December 31, 2024 by the extended November 11, 2025 deadline, breaching Listing Rule 5250(c)(1) on timely periodic reports.

What caused Sinovac Biotech’s delay in filing its 2024 Form 20-F?

The delay followed the April 15, 2025 resignation of Grant Thornton Zhitong Certified Public Accountants LLP as Sinovac’s independent registered public accounting firm, which disrupted completion of the 2024 audit and prevented timely filing of the 2024 Form 20-F.

How is Sinovac Biotech responding to the Nasdaq delisting determination?

Sinovac plans to request a hearing before a Nasdaq Hearing Panel by November 19, 2025 and intends to appeal the staff determination while working to complete and file its 2024 Annual Report to regain compliance with Nasdaq Listing Rule 5250(c)(1).

What effect does Sinovac’s hearing request have on its Nasdaq listing?

Requesting a hearing will automatically stay suspension of Sinovac’s securities for 15 days from the request date. The company also intends to seek a further stay of any suspension or delisting action while the Nasdaq Hearing Panel process is underway.

Which auditor is working on Sinovac Biotech’s 2024 financial statements?

After Grant Thornton Zhitong’s resignation in April 2025, Sinovac engaged UHY LLP as its independent registered public accounting firm and is working with UHY LLP to audit the financial statements needed to file the 2024 Form 20-F annual report.

What Nasdaq rule is Sinovac Biotech currently not complying with?

Sinovac is not in compliance with Nasdaq Listing Rule 5250(c)(1), which requires timely filing of periodic financial reports. The missed extended deadline for its Form 20-F for the year ended December 31, 2024 triggered the Nasdaq staff delisting determination.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 01/30/2026 - 03:23 PM Learn about SEC filing dates

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER

THE SECURITIES EXCHANGE ACT OF 1934

For the month of November 2025

Commission File Number: 001-32371

SINOVAC BIOTECH LTD.

No. 39 Shangdi Xi Rd, Haidian District

Beijing 100085, People’s Republic of China

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ☒ Form 40-F ☐

SIGNATURE

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, thereunto duly authorized.

	SINOVAC BIOTECH LTD.
	By:	/s/ Chiang Li
	Name:	Chiang Li
	Title:	Member of the Board

Date: November 18, 2025

1 

Exhibit Index

Exhibit 99.1 Press Release

2 

Exhibit 99.1

SINOVAC Announces Receipt of Nasdaq Notice of Delisting and Intention to Appeal

BEIJING, November 18, 2025 – Sinovac Biotech Ltd. (Nasdaq: SVA) (“SINOVAC” or the “Company”), a leading provider of biopharmaceutical products in China, announced today that on November 12, 2025, it received a delisting determination letter (the “Staff Determination”) from the Nasdaq Listing Qualifications Department of The Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that, unless the Company timely requests a hearing before the Nasdaq Hearing Panel, which the Company intends to do, the Company’s securities would be subject to suspension and delisting from Nasdaq at the opening of business on November 21, 2025 as a result of the Company’s non-compliance with Nasdaq Listing Rule 5250(c)(1) (the “Listing Rule”) for its failure to timely file its annual report on Form 20-F for the year ended December 31, 2024 (the “2024 Annual Report”) by the Extension Deadline (defined below).

The Company previously disclosed in the Notification of Late Filing on Form 12b-25, filed with the U.S. Securities and Exchange Commission on April 29, 2025, that it was unable to timely file the 2024 Annual Report due to Grant Thornton Zhitong Certified Public Accountants LLP’s resignation on April 15, 2025 as the Company’s independent registered public accounting firm. As the Company subsequently disclosed on May 23, 2025, Nasdaq granted the Company a period of 60 calendar days from the date of the initial notification on May 16, 2025 for failure to timely file the 2024 Annual Report to submit a plan to regain compliance, and subject to acceptance of such plan, a period of 180 calendar days from the prescribed due date of the 2024 Annual Report, or until November 11, 2025 (the “Extension Deadline”), to file the 2024 Annual Report to regain compliance with the Listing Rule.

As the Company announced on October 24, 2025, it has engaged UHY LLP as its independent registered public accounting firm and the Company is working diligently with UHY LLP to be able to file the 2024 Annual Report as soon as possible to regain compliance with the Listing Rule.

The Company intends to appeal the Staff Determination to enable UHY LLP sufficient time to audit the financial statements required to file the 2024 Annual Report. The Company’s request for a hearing before the Nasdaq Hearing Panel to appeal the Staff Determination must be made on or before November 19, 2025. The hearing request will automatically stay the suspension of the Company’s securities for a period of 15 days from the date of the request. The Company also intends to seek a further stay of any suspension or delisting action pending the hearing process.

About SINOVAC

Sinovac Biotech Ltd. (SINOVAC) is a China-based biopharmaceutical company that focuses on the R&D, manufacturing, and commercialization of vaccines that protect against human infectious diseases.

SINOVAC’s product portfolio includes vaccines against COVID-19, enterovirus 71 (EV71) infected Hand-Foot-Mouth disease (HFMD), hepatitis A, varicella, influenza, poliomyelitis, pneumococcal disease, etc.

The COVID-19 vaccine, CoronaVac®, has been approved for use in more than 60 countries and regions worldwide. The hepatitis A vaccine, Healive®, passed WHO prequalification requirements in 2017. The EV71 vaccine, Inlive®, is an innovative vaccine under “Category 1 Preventative Biological Products” and commercialized in China in 2016. In 2022, SINOVAC’s Sabin-strain inactivated polio vaccine (sIPV) and varicella vaccine were prequalified by the WHO.

SINOVAC was the first company to be granted approval for its H1N1 influenza vaccine Panflu.1®, which has supplied the Chinese government’s vaccination campaign and stockpiling program. The Company is also the only supplier of the H5N1 pandemic influenza vaccine, Panflu®, to the Chinese government stockpiling program.

SINOVAC continually dedicates itself to new vaccine R&D, with more combination vaccine products in its pipeline, and constantly explores global market opportunities. SINOVAC plans to conduct more extensive and in-depth trade and cooperation with additional countries, and business and industry organizations.

Safe Harbor Statement

This announcement contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, and as defined in the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as “may,” “will,” “expect,” “anticipate,” “aim,” “estimate,” “intend,” “plan,” “believe,” “potential,” “continue,” “is/are likely to” or other similar expressions. Such statements are based upon current expectations and current market and operating conditions and relate to events that involve known or unknown risks, uncertainties and other factors, including without limitation risks, uncertainties and factors related to the completion of the audits of required fiscal periods, completion and filing of the 2024 Annual Report, decisions from the Nasdaq Hearing Panel and actions taken to regain compliance with the Listing Rule, all of which are difficult to predict and many of which are beyond the Company’s or Board’s control, which may cause actual results, performance or achievements to differ materially from those in the forward-looking statements. Further information regarding these and other risks, uncertainties or factors is included in the Company’s filings with the U.S. Securities and Exchange Commission. The Company and Board do not undertake any obligation to update any forward-looking statement as a result of new information, future events or otherwise, except as required under law.

Contacts

Media Contact

FGS Global

Email: sinovac@fgsglobal.com

Investor Contact

Sinovac Biotech Ltd.

Email: ir@sinovac.com