YMAT 6-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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 December 2025.

Commission File Number 001-42767

J-Star Holding Co., Ltd.

(Translation of registrant’s name into English)

7/F-1, No. 633, Sec. 2, Taiwan Blvd.,

Xitun District, Taichung City 407,

Taiwan (R.O.C.)

(Address of principal executive office)

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

INFORMATION CONTAINED IN THIS REPORT ON FORM 6-K

Nasdaq Minimum Bid Price Deficiency Letter

J-Star Holding Co., Ltd. received a notice dated December 12, 2025, from the Listings Qualifications Department (the “Staff”) of The Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that the minimum bid price per share of its Class A ordinary shares was below $1.00 for a period of 30 consecutive business days and that the Company did not meet the minimum bid price requirement set forth in Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Price Rule”). The Nasdaq notification letter does not result in the immediate delisting of the Company’s Class A ordinary shares, and the shares will continue to trade uninterrupted under the symbol “YMAT.”

Pursuant to Nasdaq Listing Rule 5810(c)(3)(A), the Company has a compliance period of one hundred eighty (180) calendar days, or until June 10, 2026 (the “Compliance Period”), to regain compliance with Nasdaq’s minimum bid price requirement. If at any time during the Compliance Period, the closing bid price per share of the Company’s Class A ordinary shares is at least $1.00 for a minimum of ten (10) consecutive business days, Nasdaq will provide the Company a written confirmation of compliance and the matter will be closed.

In the event the Company does not regain compliance by June 10, 2026, the Company may be eligible for an additional 180 calendar day grace period. To qualify, the Company will be required to meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market, with the exception of the bid price requirement, and will need to provide written notice of its intention to cure the deficiency during the second compliance period, including by effecting a reverse stock split, if necessary. If the Company chooses to implement a reverse stock split, it must complete the split no later than ten (10) business days prior to June 10, 2026, or the expiration of the second compliance period if granted.

This information is being provided solely to comply with NASDAQ Listing Rules requiring public announcement of the Company’s receipt of the letter from NASDAQ.

On December 16, 2025, the Company issued a press release entitled “J-Star Announces Receipt of Nasdaq Notification Letter Regarding Minimum Bid Price Deficiency” A copy of the press release is furnished herewith as Exhibit 99.1 and is incorporated herein by reference

EXHIBIT INDEX

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, thereunto duly authorized.

Exhibit 99.1

J-Star Announces Receipt of Nasdaq Notification Letter

Regarding Minimum Bid Price Deficiency

Taichung City, Taiwan, December 16, 2025 – J-Star Holding Co., Ltd. (Nasdaq: YMAT) (“J-Star” or the “Company”), a leading provider of innovative carbon fiber and composite solutions across a wide range of applications including personal sports equipment, healthcare products, automobile parts, resin systems, and research and development services, today announced it has received a letter of noncompliance from The Nasdaq Stock Market LLC (“Nasdaq”), dated December 12, 2025, notifying the Company that based on J-Star’s closing bid price for the last 30 consecutive business days, the Company no longer meets the continued listing requirement of Nasdaq, under Nasdaq Listing Rules 5550(a)(2), to maintain a minimum bid price of $1 per share.

However, pursuant to Nasdaq Listing Rule 5810(c)(3)(A), the Company has a compliance period of 180 calendar days in which to regain compliance. If at any time during this 180-day period the closing bid price of the Company’s security is at least $1 for a minimum of ten consecutive business days, Nasdaq will provide J-Star with written confirmation of compliance and this matter will be closed.

In the event the Company does not regain compliance, J-Star may be eligible for additional time. To qualify, the Company will be required to meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for The Nasdaq Capital Market, with the exception of the bid price requirement, and will need to provide written notice of its intention to cure the deficiency during the second compliance period, by effecting a reverse stock split, if necessary. If J-Star meets these requirements, Nasdaq will inform the Company that it has been granted an additional 180 calendar days. However, if it appears to Nasdaq that the Company will not be able to cure the deficiency, or if the Company is otherwise not eligible, Nasdaq will provide notice that its securities will be subject to delisting.

The Nasdaq notification letter does not result in the immediate delisting of the Company’s Class A ordinary shares, and the shares will continue to trade uninterrupted under the symbol “YMAT.”

J-Star is currently evaluating options to regain compliance and intends to timely regain compliance with Nasdaq’s continued listing requirement. Although J-Star will use all reasonable efforts to achieve compliance with Rule 5550(a)(2), there can be no assurance that the Company will be able to regain compliance with that rule or will otherwise be in compliance with other Nasdaq continued listing requirement.

About J-Star Holding Co., Ltd.

J-Star (NASDAQ: YMAT) is a holding company with operations conducted through subsidiaries in Taiwan, Hong Kong, and Samoa with its headquarters in Taiwan. J-Star’s predecessor group was established in 1970, and has accumulated over 50 years of know-how in material composites industry. J-Star develops and commercializes the technology on carbon reinforcement and resin systems. With decades of experience and knowledge in composites and materials, J-Star is able to apply its expertise and technology to design and manufacture a great variety of lightweight, high-performance carbon composite products, ranging from key structural parts of electric bicycles and sports bicycles, rackets, automobile parts to healthcare products. Visit j-starholding.com and ymaunivers.com to learn more.

Forward Looking-Statements

Certain statements contained in this press release about future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These statements include, but are not limited to, statements relating to the expected trading commencement and closing dates. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: the uncertainties related to market conditions and other factors discussed in the “Risk Factors” section of the final prospectus filed with the SEC. For these reasons, among others, investors are cautioned not to place undue reliance upon any forward-looking statements in this press release. Any forward-looking statements contained in this press release speak only as of the date hereof, and J-Star specifically disclaims any obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law.

Contact:

Matt Chesler, CFA

FNK IR

646-809-2183

[email protected]