X0508 4 2026-01-16 0 0001111928 IPG PHOTONICS CORP IPGP 0001130423 IP FIBRE DEVICES LTD C/O IPG PHOTONICS CORPORATION 377 SIMARANO DRIVE MARLBOROUGH MA 01752 0 0 1 0 1 Common Stock 2026-01-16 4 S 0 14511 79.54 D 6642825 D Common Stock 2026-01-16 4 S 0 14656 80.20 D 6628169 D Common Stock 2026-01-20 4 S 0 7659 78.92 D 6620510 D Common Stock 2026-01-20 4 S 0 13960 80.43 D 6606550 D Common Stock 2026-01-21 4 S 0 1306 80.34 D 6605244 D Common Stock 2026-01-21 4 S 0 12075 81.65 D 6593169 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 13, 2025. The reported transaction involves sale transactions ranging from $78.93 to $79.90 per share. The weighted average price per share was $79.54. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price. The reported transaction involves sale transactions ranging from $80.00 to $80.79 per share. The weighted average price per share was $80.20. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price. The reported transaction involves sale transactions ranging from $78.65 to $79.52 per share. The weighted average price per share was $78.92. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price. The reported transaction involves sale transactions ranging from $79.66 to $80.45 per share. The weighted average price per share was $80.43. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price. The reported transaction involves sale transactions ranging from $79.68 to $80.60 per share. The weighted average price per share was $80.34. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price. The reported transaction involves sale transactions ranging from $80.89 to $81.72 per share. The weighted average price per share was $81.65. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer, information regarding the number of shares sold at each separate price. /s/ Adam N. King, Attorney-in-Fact 2026-01-21