[6-K] CHIPMOS TECHNOLOGIES INC Current Report (Foreign Issuer)

Rhea-AI Filing Summary

ChipMOS TECHNOLOGIES INC. reported the expiration and results of its share repurchase program. The company repurchased 12,717,000 shares during 2025/09/03–2025/10/31 for a total of NTD 365,222,801 at an average price of NTD 28.72.

The plan authorized up to 15,000,000 shares within a price range of NTD 16.80–32.00 for the 2025/09/03–2025/11/01 period. Management cited a phased approach within the set range as the reason the full amount was not executed. Cumulative treasury shares now total 21,822,000, representing 3.04% of issued shares.

Insights

Equity Capital Markets Analyst

Neutral: routine buyback update with partial execution.

ChipMOS completed a buyback window, purchasing 12,717,000 shares for NTD 365,222,801 at an average of NTD 28.72, within its disclosed price band. The authorization permitted up to 15,000,000 shares, but the company used a phased approach tied to price movements.

The update is administrative and does not alter strategy or guidance. Treasury shares now stand at 21,822,000 (3.04%) of issued shares. Actual impact depends on future capital allocation decisions and any subsequent programs disclosed.

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 October 2025

Commission File Number 001-37928

ChipMOS TECHNOLOGIES INC.

(Translation of Registrant’s Name Into English)

No. 1, R&D Rd. 1, Hsinchu Science Park

Hsinchu, Taiwan

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 ☐

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.

						ChipMOS TECHNOLOGIES INC.
						(Registrant)
Date: October 31, 2025				By		/S/ S. J. Cheng
				Name:		S. J. Cheng
				Title:		Chairman & President

English translation of Company’s October 31, 2025 filing with the Taiwan Stock Exchange Corporation’s (“TWSE”)
Market Observation Post System (“MOPS”).

Date of announcement: 2025/10/31

Subject: Announcement of the Company’s shares repurchase expiration and execution status

Date of events: 2025/11/01

To which item it meets: Article 4, Paragraph 1, Item 35 of the Taiwan Stock Exchange Corporation Procedures for Verification and Disclosure of Material Information of Companies with Listed Securities

Statement:

1.Originally determined ceiling on total monetary amount of the share repurchase (NTD): 16,214,828,000

2.Originally scheduled period for the repurchase: 2025/09/03~2025/11/01

3.Originally determined number of shares to be repurchased (shares): 15,000,000

4.Originally determined repurchase price range (NTD): 16.80~32.00

5.Actual period of the current repurchase: 2025/09/03~2025/10/31

6.Number of shares currently repurchased (shares): 12,717,000

7.Total monetary amount of shares currently repurchased (NTD): 365,222,801

8.Current average repurchase price per share (NTD): 28.72

9.Cumulative number of the company’s own shares held (shares): 21,822,000

10.Cumulative number of the company’s own shares as a percentage of the total number of the company’s issued shares (%): 3.04

11.Reason for non-completion of the current share repurchase: In order to protect the interests of shareholders and take into account the market mechanisms, the Company adopted a phased repurchase strategy within the price range depending on the stock price changes. As the result, the repurchase was not fully executed.

12.Any other matters that need to be specified: Because the last day of the repurchase period would fall on a holiday, so the announcement was made after the market closed on the last trading day of the period.

FAQ

What did ChipMOS (IMOS) repurchase in its latest buyback window?

ChipMOS repurchased 12,717,000 shares for a total of NTD 365,222,801 at an average price of NTD 28.72.

What was the authorized size and price range of ChipMOS’s buyback?

The plan authorized up to 15,000,000 shares within a price range of NTD 16.80–32.00.

When did the ChipMOS buyback occur?

The actual repurchase period ran from 2025/09/03 to 2025/10/31.

Why didn’t ChipMOS repurchase the full authorized amount?

Management used a phased repurchase strategy within the price range based on stock price changes, so the plan was not fully executed.

How many treasury shares does ChipMOS now hold?

Cumulative treasury shares total 21,822,000, equal to 3.04% of issued shares.

What was the original buyback window for ChipMOS?

The originally scheduled period was 2025/09/03–2025/11/01.