The markets closed flat with the Dow adding 5 points to 23,930 after worker productivity rose by a less than expected 0.7% in the first quarter. Nasdaq slipped 12 points to 7088.

On the upside

Shares of Inspire Medical Systems (NYSE: INSP) surged in its market debut.

STAAR Surgical (Nasdaq: STAA) reversed year ago losses to post a profit for the first quarter.

Coherus BioSciences (Nasdaq: CHRS) has resubmitted its biologics license application for CHS-1701.

On the downside

LSC Communications (NYSE: LKSD) widened first quarter losses more than expected.

Shares of Esperion Therapeutics (Nasdaq: ESPR) extended their losses.

The Food and Drug Adminstration's Antimicrobial Drugs Advisory Committee voted 11 to 4 that Achaogen (Nasdaq: AKAO) failed to provide substantial evidence of safety and effectiveness of plazomicin to treat bloodstream infections.

In the broad market, declining issues outpaced advancers by a margin of nearly 3 to 2 on the NYSE and by more than 5 to 3 on Nasdaq. The broader S&P 500 lost 5 points to 2,629. Bitcoin jumped $433 to $9,653.