AtriCure, Inc. — Director's Dealing 2010

Nov 2, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AtriCure, Inc. (ATRC)
CIK: 0001323885
Period of Report: 2010-11-01

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
2010-11-01	Common Stock	P	28847	$8.0979	Acquired	1347379	Indirect
2010-11-01	Common Stock	P	4853	$8.0979	Acquired	230328	Indirect
2010-11-02	Common Stock	P	31508	$8.0877	Acquired	230328	Indirect
2010-11-02	Common Stock	P	5300	$8.0877	Acquired	235628	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: 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.

F3: This transaction was executed in multiple trades at prices ranging from $8.00to $8.19. 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."

F4: This transaction was executed in multiple trades at prices ranging from $7.90 to $8.15. 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