What happened

Shares of GoPro (GPRO 1.63%) have popped today, up by 12% as of 2:30 p.m. EDT, after Prentice Capital Management disclosed that it had boosted its stake in the action-camera maker. Separately, the company also said it had started shipping the Hero 8 Black, its latest flagship camera.

So what

In a regulatory filing on Friday, Prentice said it now holds nearly 12.5 million GoPro shares, representing an approximately 10% stake in the company. That's up from the 7.9 million shares, a 6.5% stake, that the hedge fund had previously disclosed in a similar filing from August.

Hero 8 Black getting splashed in water

Hero 8 Black. Image source: GoPro.

With the increased position, Prentice is now the largest institutional shareholder in GoPro, topping the 10.9 million shares that Vanguard holds across various funds. The next largest investor behind Vanguard is Blackrock, with 8.4 million shares.

Now what

Once a high-flying growth stock, GoPro has been on the ropes in recent years as investors wonder if the company can pull off a turnaround. Shares have lost 75% of their value over the past three years, while the S&P 500 has marched higher by nearly 40%. Investors are cheering the vote of confidence from Prentice, which is managed by Michael Zimmerman, a former trader at SAC Capital.

GoPro announced the Hero 8 Black earlier this month, which is priced at $399 and was initially scheduled to start shipping on Oct. 15. Launching the product a few days early should let the company capture a few more sales.