Sarepta Therapeutics' stock increased by 30.1% after U.S. regulators approved the use of its medicine for children with Duchenne muscular dystrophy who are at least 4 years old.
The S&P 500 slipped 0.2% on Friday but remained close to its all-time high set on Tuesday. This capped its eighth winning week in the last nine. Overall, the S&P 500 dipped 8.55 points to 5,464.62.
Smith & Wesson Brands' stock tumbled due to the traditionally slower season for firearms during the summer, according to CEO Mark Smith. Despite reporting stronger profits for the latest quarter than analysts expected, the stock dropped 12.9%.