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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 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* Cross Atlantic Capital Partners, Inc. (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Rubicon Technology, Inc. [ RBCN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 03/22/2013
	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								15,781	I	See footnotes.(1)(2)
Common Stock	03/22/2013		S		81,681	D	$6.04(3)	5,304,742(4)	D
Common Stock	03/25/2013		S(5)		200,000	D	$6.2548	5,104,742(4)(6)	D
Common Stock	03/26/2013		S(5)		100,000	D	$6.6661(7)	5,004,742(4)(8)	D

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* Cross Atlantic Capital Partners, Inc. (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* CROSS ATLANTIC TECHNOLOGY FUND L P (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* XATF Management, L.P. (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* CROSS ATLANTIC TECHNOLOGY FUND II LP (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* XATF MANAGEMENT II LP (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* CROSS ATLANTIC CAPITAL PARTNERS II INC (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* CO INVESTMENT 2000 FUND LP (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Co-Invest Management LP (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Co-Invest Capital Partners Inc (Last) (First) (Middle) FIVE RADNOR CORPORATE CENTER, SUITE 555 100 MATSONFORD ROAD (Street) RADNOR PA 19087 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. These securities are held by Donald R. Caldwell ("Caldwell"), a director of the Issuer, who is the owner and director of Cross Atlantic Capital Partners, Inc., which is the general partner of XATF Management L.P., which is the general partner of Cross Atlantic Technology Fund, L.P. Caldwell is a director, shareholder and officer of Cross Atlantic Capital Partners II, Inc., which is the general partner of XATF Management II, L.P., which is the general partner of Cross Atlantic Technology Fund II, L.P. Caldwell is a shareholder, director and officer of Co-Invest Capital Partners, Inc., which is the general partner of Co-Invest Management, L.P., which is the general partner of The Co-Investment 2000 Fund, L.P. Cross Atlantic Technology Fund, L.P, Cross Atlantic Technology Fund II, L.P. and The Co-Investment 2000 Fund, L.P. are collectively referred to as the "Funds". (Continued in footnote 2)

2. Under the terms of the applicable partnership agreements of the Funds, Caldwell is deemed to hold these securities for the benefit of the Funds, which are entitled to receive the net economic benefit of the securities as a credit against the management fees owed by the funds to Cross Atlantic Capital Partners, Inc. The Funds disclaim beneficial ownership of the securities except to the extent of their pecuniary interest therein.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.00 to $6.05 inclusive. The reporting persons undertake to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price set forth within the ranges set forth in the footnotes to this Form 4.

4. Consists of shares directly held by the Funds as follows: Cross Atlantic Technology Fund, L.P. holds 586,891 shares of common stock, Cross Atlantic Technology Fund II, L.P. holds 2,230,198 shares of common stock and The Co-Investment 2000 Fund, L.P. holds 2,487,653 shares of common stock.

5. Sale(s) effected pusuant to a Rule 10b5-1 trading plan adopted on February 25, 2013.

6. Consists of shares directly held by the Funds as follows: Cross Atlantic Technology Fund, L.P. holds 386,891 shares of common stock, Cross Atlantic Technology Fund II, L.P. holds 2,230,198 shares of common stock and The Co-Investment 2000 Fund, L.P. holds 2,487,653 shares of common stock.

7. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.50 to $6.80 inclusive. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price set forth within the ranges set forth in this footnote.

8. Cross Atlantic Technology Fund, L.P. holds 286,891 shares of common stock, Cross Atlantic Technology Fund II, L.P. holds 2,230,198 shares of common stock and The Co-Investment 2000 Fund, L.P. holds 2,487,653 shares of common stock.

	/s/ Donald R. Caldwell, Authorized Officer	03/26/2013
	** 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 4 (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.