X0303 4 2011-05-24 0 0001037760 CEPHEID CPHD 0001263113 PERSING DAVID H C/O CEPHEID 904 CARIBBEAN DRIVE SUNNYVALE CA 94089 1 1 0 0 Exec VP,Chief Med/Tech Officer Common Stock 2011-05-24 4 M 0 50000 7.38 A 51354 D Common Stock 2011-05-24 4 S 0 50000 30.1283 D 1354 D Non-Qualified Stock Option (right to buy) 7.38 2011-05-24 4 M 0 50000 0.00 D 2015-08-29 Common Stock 50000 81750 D The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 24, 2011. Represents the aggregate of sales effected on the same day at different prices pursuant to the plan in footnote (1). Represents the weighted average sales price per share. The shares sold at prices ranging from $29.70 to $30.65 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. The stock option grant is 100% vested and immediately exercisable. /s/ David H. Persing by Joseph H. Smith, Attorney-in-Fact 2011-05-25