SEC FORM 3

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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:		3235-0104
Expires:	February 28, 2011
Estimated average burden
hours per response		0.5

1. Name and Address of Reporting Person^*

INSTITUTIONAL VENTURE PARTNERS X LP

(Last)

(First)

(Middle)

3000 SAND HILL ROAD, SUITE 2-250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
02/14/2008

3. Issuer Name and Ticker or Trading Symbol
ArcSight Inc [ ARST ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

Director	X	10% Owner
Officer (give title below)		Other (specify below)

5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	409,566	I	By Institutional Venture Partners X, L.P. ^{( 1 )}
Common Stock	90,433	I	By Institutional Venture Partners X GmbH & Co. Beteiligungs KG ^{( 2 )}

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Series A Preferred Stock	^{( 3 )}	^{( 3 )}	Common Stock	772,999	^{( 3 )}	I	By Institutional Venture Partners X, L.P. ^{( 1 )}
Series A Preferred Stock	^{( 3 )}	^{( 3 )}	Common Stock	170,680	^{( 3 )}	I	By Institutional Venture Partners X GmbH & Co. Beteiligungs KG ^{( 2 )}
Series B Preferred Stock	^{( 4 )}	^{( 4 )}	Common Stock	1,231,382	^{( 4 )}	I	By Institutional Venture Partners X, L.P. ^{( 1 )}
Series B Preferred Stock	^{( 4 )}	^{( 4 )}	Common Stock	271,892	^{( 4 )}	I	By Institutional Venture Partners X GmbH & Co. Beteiligungs KG ^{( 2 )}

1. Name and Address of Reporting Person^*

INSTITUTIONAL VENTURE PARTNERS X LP

(Last)

(First)

(Middle)

3000 SAND HILL ROAD, SUITE 2-250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

Institutional Venture Partners X GmbH & Co. Beteiligungs KG

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BUILDING 2, SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

Institutional Venture Management X, LLC

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BUILDING 2, SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

Phelps Dennis B

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BUILDING 2, SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

Harrick Stephen J

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BUILDING 2, SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

FOGELSONG NORMAN A

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BUILDING 2, SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

ELMORE MARY JANE

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BLDG 2SUITE 290

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

DENNIS REID W

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BUILDING 2, SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

1. Name and Address of Reporting Person^*

Chaffee Todd C

(Last)

(First)

(Middle)

3000 SAND HILL ROAD

BUILDING 2, SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Explanation of Responses:

1. The shares are owned by Institutional Venture Partners X, L.P. ("IVP X "), which is under common control with Institutional Venture Partners X GmbH & Co. Beteiligungs KG ("IVP X KG"). Institutional Venture Management X, LLC ("IVM X") serves as the sole General Partner of IVP X. Todd C. Chaffee ("Chaffee"), Reid W. Dennis ("Dennis"), Mary Jane Elmore ("Elmore"), Norman A. Fogelsong ("Fogelsong"), Stephen J. Harrick ("Harrick") and Dennis B. Phelps ("Phelps") are the Managing Directors of IVM X and share voting and dispositive power over the shares held by IVP X. Each of these individuals disclaims beneficial ownership of the shares reported herein, except to the extent of his or her respective pecuniary interest therein.

2. These shares are held by IVP X KG, which is under common control with IVP X. IVM X is the Managing Limited Partner of IVP X KG. Chaffee, Dennis, Elmore, Fogelsong, Harrick and Phelps are the Managing Directors of IVM X and share voting and dispositive power over the shares held by IVP X KG. Each of these individuals disclaims beneficial ownership of the shares reported herein, except to the extent of his or her respective pecuniary interest therein.

3. The Issuer's Series A Preferred Stock will automatically convert into Common Stock on a 1 to 1.25824093282596 basis upon the closing of the Issuer's initial public offering.

4. The Issuer's Series B Preferred Stock will automatically convert into Common Stock on a 1 to 1 basis upon the closing of the Issuer's initial public offering.

Remarks:

	/s/ Norman Fogelsong, Managing Director	02/14/2008
	Norman Fogelsong, Managing Director	02/14/2008
	Norman Fogelsong, Managing Director	02/14/2008
	Melanie Chladek, Attorney-in-Fact for Dennis Phelps	02/14/2008
	Melanie Chladek, Attorney-in-Fact for Stephen Harrick	02/14/2008
	Melanie Chladek, Attorney-in-Fact for NORMAN FOGELSONG	02/14/2008
	Melanie Chladek, Attorney-in-Fact for Mary Elmore	02/14/2008
	Melanie Chladek, Attorney-in-Fact for Reid Dennis	02/14/2008
	Melanie Chladek, Attorney-in-Fact for Todd Chaffee	02/14/2008
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.