SEC Form 4

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) 12/11/2007
	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	12/11/2007		S		18,731 ( 1 )	D	$20.2277	1,162,903	I	See Footnote 6 ( 6 )
Common Stock	12/11/2007		S		8,746 ( 2 )	D	$20.2277	542,991	I	See Footnote 7 ( 7 )
Common Stock	12/11/2007		S		8,097 ( 3 )	D	$20.2277	502,849	I	See Footnote 8 ( 8 )
Common Stock	12/11/2007		S		317 ( 4 )	D	$20.2277	19,622	I	See Footnote 9 ( 9 )
Common Stock	12/11/2007		S		550 ( 5 )	D	$20.2277	34,104	I	See Footnote 10 ( 10 )
Common Stock	12/12/2007		S		11,086 ( 1 )	D	$19.9893	1,151,817	I	See Footnote 6 ( 6 )
Common Stock	12/12/2007		S		5,177 ( 2 )	D	$19.9893	537,814	I	See Footnote 7 ( 7 )
Common Stock	12/12/2007		S		4,804 ( 3 )	D	$19.9893	498,045	I	See Footnote 8 ( 8 )
Common Stock	12/12/2007		S		183 ( 4 )	D	$19.9893	19,439	I	See Footnote 9 ( 9 )
Common Stock	12/12/2007		S		321 ( 5 )	D	$19.9893	33,783	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.

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	12/12/2007
	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	12/12/2007
	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	12/12/2007
	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	12/12/2007
	TA Executives Fund LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	12/12/2007
	TA Investors LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	12/12/2007
	TA Associates IX LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	12/12/2007
	TA Associates VIII LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer	12/12/2007
	TA Associates AP IV L.P., By TA Associates, Inc., Its General Partner, By Thomas P. Alber, Chief Financial Officer	12/12/2007
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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