Amkor Technology (AMKR) is down about 3.25% in Monday trading as the market reacts to a secondary underwritten public offering by 915 Investments, LP, an investment vehicle tied to members of the Kim family and board chair Susan Y. Kim. The seller plans to offer 10,000,000 shares, with underwriters holding a 30-day option to buy up to an additional 1,500,000 shares, increasing near-term share supply and weighing on the stock. (seekingalpha.com)

The offering is entirely from the selling stockholder; Amkor is not selling shares and will not receive any proceeds. That structure can still pressure the stock because it increases float and can be interpreted as a major holder monetizing gains after a strong run. (seekingalpha.com)

AMKR has been volatile heading into its next earnings report scheduled for after the close on Monday, April 27, 2026, making the stock more sensitive to near-term catalysts like share-sale headlines. With sentiment already elevated into the print, an incremental supply event can trigger profit-taking and risk reduction. (marketbeat.com)

Investors will watch for final pricing and allocation details, whether the overallotment is exercised, and how quickly the new shares are absorbed by demand. Attention will also shift to Amkor’s earnings and forward guidance on advanced packaging demand, utilization, and margins, which could either stabilize the stock or compound the post-offering move.