SEC Form 6-K filed by J-Star Holding Co. Ltd.

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.