X0202 4 2007-09-25 0001111928 IPG PHOTONICS CORP IPGP 0001130421 GAPONTSEV VALENTIN P C/O IPG PHOTONICS CORPORATION 50 OLD WEBSTER ROAD OXFORD MA 01540 1 1 1 0 CEO & Chairman of the Board Common Stock 2007-09-25 4 S 0 15681 18.814 D 8171002 I Through IP Fibre Devices (UK) Ltd. Common Stock 2007-09-26 4 S 0 150 20.00 D 11778425 D Common Stock 2007-09-26 4 S 0 150 20.00 D 8170852 I Through IP Fibre Devices (UK) Ltd. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 23, 2007. Sales ranged from $18.62 to $18.94 as follows: 66 shares at $18.62; 133 shares at $18.64; 399 shares at $18.65; 199 shares at $18.67; 66 shares at $18.68; 930 shares at $18.69; 332 shares at $18.70; 7 shares at $18.71; 664 shares at $18.72; 214 shares at $18.73; 318 shares at $18.74; 865 shares at $18.75; 133 shares at $18.76; 399 shares at $18.78; 797 shares at $18.79; 465 shares at $18.80; 664 shares at $18.81; 1,927 shares at $18.82; 266 shares at $18.83; 598 shares at $18.84; 465 shares at $18.85; 66 shares at $18.86; 1,661 shares at $18.87; 930 shares at $18.88; 193 shares at $18.89; 1,528 shares at $18.90; 466 shares at $18.91; 598 shares at $18.92; 133 shares at $18.93; 66 shares at $18.95; 133 shares at $18.94. The reporting person is the managing director of IP Fibre Devices (UK) Ltd. and has voting and investment power with respect to the shares held of record by IP Fibre Devices (UK) Ltd. The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of the beneficial ownership of all the reported shares for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. Angelo P. Lopresti, Attorney-in-fact 2007-09-27