Form 4 Filed by Ta Investors Llc on May 15, 2008

This form 4 (insider trading filing) was submitted to the Securities and Exchange Commission (SEC) by insider Ta Investors Llc on May 15, 2008. The CIK number of this insider is 1235809. At the time of this reporting, Ta Investors Llc is the Other of Ipg Photonics Corp . See all insider stock transactions reported by Ta Investors Llc and all stock buys, sales, and option exercises made by insiders at Ipg Photonics Corp . The stock ticker symbol of Ipg Photonics Corp is IPGP.

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Expires: February 28, 2011 Estimated average burden hours per response 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* TA ASSOCIATES INC (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST, 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol IPG PHOTONICS CORP [ IPGP ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) X Other (specify below) See General Remarks
	3. Date of Earliest Transaction (Month/Day/Year) 05/13/2008
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/13/2008		S ( 11 )		18,658 ( 1 )	D	$19.0434	1,062,798	I	See Footnote 6 ( 6 )
Common Stock	05/13/2008		S ( 11 )		8,712 ( 2 )	D	$19.0434	496,248	I	See Footnote 7 ( 7 )
Common Stock	05/13/2008		S ( 11 )		8,066 ( 3 )	D	$19.0434	459,561	I	See Footnote 8 ( 8 )
Common Stock	05/13/2008		S ( 11 )		316 ( 4 )	D	$19.0434	17,931	I	See Footnote 9 ( 9 )
Common Stock	05/13/2008		S ( 11 )		548 ( 5 )	D	$19.0434	31,168	I	See Footnote 10 ( 10 )
Common Stock	05/14/2008		S ( 11 )		34,387 ( 1 )	D	$19.0822	1,028,411	I	See Footnote 6 ( 6 )
Common Stock	05/14/2008		S ( 11 )		16,056 ( 2 )	D	$19.0822	480,192	I	See Footnote 7 ( 7 )
Common Stock	05/14/2008		S ( 11 )		14,865 ( 3 )	D	$19.0822	444,696	I	See Footnote 8 ( 8 )
Common Stock	05/14/2008		S ( 11 )		582 ( 4 )	D	$19.0822	17,349	I	See Footnote 9 ( 9 )
Common Stock	05/14/2008		S ( 11 )		1,010 ( 5 )	D	$19.0822	30,158	I	See Footnote 10 ( 10 )
Common Stock	05/15/2008		S ( 11 )		38,550 ( 1 )	D	$19.1754	989,861	I	See Footnote 6 ( 6 )
Common Stock	05/15/2008		S ( 11 )		18,000 ( 2 )	D	$19.1754	462,192	I	See Footnote 7 ( 7 )
Common Stock	05/15/2008		S ( 11 )		16,666 ( 3 )	D	$19.1754	428,030	I	See Footnote 8 ( 8 )
Common Stock	05/15/2008		S ( 11 )		652 ( 4 )	D	$19.1754	16,697	I	See Footnote 9 ( 9 )
Common Stock	05/15/2008		S ( 11 )		1,132 ( 5 )	D	$19.1754	29,026	I	See Footnote 10 ( 10 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* TA ASSOCIATES INC (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST, 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA IX LP (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST. 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA ASSOCIATES IX LLC (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST. 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA ADVENT VIII LP (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST, 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA ASSOCIATES VIII LLC (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST, 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA / ATLANTIC & PACIFIC IV LP (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST. 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA ASSOCIATES AP IV LP (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST. 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA EXECUTIVES FUND LLC (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST, 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

1. Name and Address of Reporting Person* TA INVESTORS LLC (Last) (First) (Middle) JOHN HANCOCK TOWER 200 CLARENDON ST, 56TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)

Explanation of Responses:

1. These securities were sold solely by TA IX L.P.

2. These securities were sold solely by TA/Advent VIII L.P.

3. These securities were sold solely by TA/Atlantic and Pacific IV L.P.

4. These securities were sold solely by TA Executives Fund LLC.

5. These securities were sold solely by TA Investors LLC.

6. These securities are owned solely by TA IX L.P. TA Associates, Inc. is the Manager of TA Associates IX LLC, which is the General Partner of TA IX L.P. Each of TA Associates, Inc. and TA Associates IX LLC may be deemed to have a beneficial interest in shares held by TA IX L.P. and each disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.

7. These securities are owned solely by TA/Advent VIII L.P. TA Associates, Inc. is the Manager of TA Associates VIII LLC, which is the General Partner of TA/Advent VIII L.P. Each of TA Associates, Inc. and TA Associates VIII LLC may be deemed to have a beneficial interest in shares held by TA/Advent VIII L.P. and each disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.

8. These securities are owned solely by TA/Atlantic and Pacific IV L.P. TA Associates, Inc. is the General Partner of TA Associates AP IV L.P., which is the General Partner of TA/Atlantic and Pacific IV L.P. Each of TA Associates, Inc. and TA Associates AP IV L.P. may be deemed to have a beneficial interest in shares held by TA/Atlantic and Pacific IV L.P. and each disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.

9. These securities are owned solely by TA Executives Fund LLC. TA Associates, Inc. is the Manager of TA Executives Fund LLC. TA Associates, Inc. may be deemed to have a beneficial interest in shares held by TA Executives Fund LLC and disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.

10. These securities are owned solely by TA Investors LLC. TA Associates, Inc. is the Manager of TA Investors LLC. TA Associates, Inc. may be deemed to have a beneficial interest in shares held by TA Investors LLC and disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.

11. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by TA Associates, Inc. on December 14, 2007 and amended on March 14, 2008.

Remarks:

The Reporting Persons have a representative on the Issuer's board of Directors. Michael Child currently serves as the Reporting Persons' representative on the board of directors and, as such, the reporting persons are deemed directors of the issuer.

	TA Associates, Inc., By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA IX L.P., By TA Associates IX LLC, Its General Partner, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA/Advent VIII L.P., By TA Associates VIII LLC, Its General Partner, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA/Atlantic and Pacific IV L.P., By TA Associates AP IV L.P., Its General Partner, By TA Associates, Inc., Its General Partner, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA Executives Fund LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA Investors LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA Associates IX LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA Associates VIII LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	TA Associates AP IV L.P., By TA Associates, Inc., Its General Partner, By Thomas P. Alber, Chief Financial Officer	05/15/2008
	** Signature of Reporting Person	Date
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