Biogen and American Express rise; Symantec plunges

Stocks that moved substantially or traded heavily on Friday:

Symantec Corp., down $9.66 to $19.52

The security software maker gave weak forecasts and disclosed an internal investigation.

Yelp Inc., down $3.73 to $44.02

Investors were disappointed with the online business reviews company's forecasts.

Nvidia Corp., down $5.60 to $254.53

The chipmaker had a solid quarter but shed some of its recent gains.

Biogen Inc., up $8.39 to $282.39

Drugmakers rose as President Donald Trump announced a series of proposals to limit drug prices.

TiVo Corp., down 17 cents to $13.88

The digital video recording company took a bigger-than-expected loss and reported weak revenue.

American Express Co., up 4 cents to $101.42

Financial companies fared better than the rest of the market Friday.

Flowserve Corp., down $4.35 to $43.53

The maker of pumps, valves and other parts for oil and gas companies had a mixed first quarter.

Trade Desk Inc., up $22.88 to $75.61

The digital advertising platform company raised its annual forecasts after a strong first quarter.