Square plummets, GoPro sinks, Herbalife surges

Here are some of the stocks the Yahoo Finance team will be watching for you today.

GoPro (GPRO) shares sank in early trading. The wearable camera maker delivered a wider-than-expected loss for the first quarter and even though revenue topped expectations, sales fell 49% from a year ago to $183.5 million. The sales decline prompted the company to delay the release of its much-anticipated Karma drone until the holiday season.

Square (SQ) shares were sharply lower after the payment processing firm reported a steeper-than-expected loss for the first three months of the year due to higher operating costs, but revenue beat analysts' estimates with sales up 51% from a year ago to $379 million. And the company's CEO Jack Dorsey says "the core business is really strong" and the company raised its outlook for the year.

Herbalife (HLF) rolled out a double dose of good news late yesterday. It reported better-than-expected results, and the company also said it's close to a settlement with the Federal Trade Commission regarding an investigation into the company's business practices and whether it's a pyramid scheme. This is another blow to activist investor Bill Ackman, who has been shorting the company since 2012.

Meanwhile, an Ackman favorite—Valeant (VRX)—fell in early trading after the embattled Canadian drug company admitted that it has made mistakes in the past with how it priced its drugs and is now forming a committee aimed at preventing a repeat of the same errors under new CEO John Papa.