AtriCure, Inc. — Director's Dealing 2010

Nov 9, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AtriCure, Inc. (ATRC)
CIK: 0001323885
Period of Report: 2010-11-05

Reporting Person: Discovery Group I, LLC (10% Owner)
Reporting Person: Murphy Michael R (10% Owner)
Reporting Person: Donoghue Daniel J (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-11-05	Common Stock	P	10644	$8.2293	Acquired	1389531	Indirect
2010-11-05	Common Stock	P	1791	$8.2293	Acquired	237419	Indirect
2010-11-08	Common Stock	P	9127	$8.1879	Acquired	1398658	Indirect
2010-11-08	Common Stock	P	1535	$8.1879	Acquired	238954	Indirect
2010-11-09	Common Stock	P	4229	$8.1532	Acquired	1402887	Indirect
2010-11-09	Common Stock	P	712	$8.1532	Acquired	239666	Indirect

Footnotes

F1: Discovery Group I, LLC is the General Partner of Discovery Equity Partners, L.P., which is a discretionary client of the reporting person,
that owns the reported securities. The reporting person disclaims beneficial ownership of the reported securities except to the extent of
its pecuniary interest therein

F2: This transaction was executed in multiple trades at prices ranging from $8.10to $8.25. The price reported above reflects the weighted average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder ofthe issuer full information regarding the number of shares and prices at which the transaction was effected."

F3: Discovery Group I, LLC is an investment manager for Pleiades Investment Partners - D, L.P., which is a discretionary client of the reporting
person, that owns the reported securities. The reporting person disclaims beneficial ownership of the reported securities except to the
extent of its pecuniary interest therein

F4: This transaction was executed in multiple trades at prices ranging from $8.15 to $8.20. The price reported above reflects the weighted
average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of
the issuer full information regarding the number of shares and prices at which the transaction was effected

F5: This transaction was executed in multiple trades at prices ranging from $8.08 to $8.25. The price reported above reflects the weighted
average purchase price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of
the issuer full information regarding the number of shares and prices at which the transaction was effected