GoPro plunges after charity breaks lockup

GoPro shares fell more than 12 percent on Thursday after news that founders Nicholas and Jill Woodman are breaking a lockup on their shares to set up a new charity.

However, a source told CNBC that none of Nick's shares were sold in the market Thursday and that the shares were moved from one of his personal accounts to a new foundation account for tax reasons.

No structure is in place for the sale of the shares, which is not expected to happen for some time, the source said.

The existing lockup officially ends in December, so the shift would not have been able to go into effect until January 2015.

JPMorgan Securities, which managed the company's June initial public offering, agreed to release the new foundation from a lockup restriction on about 5.8 million shares gifted to it, a GoPro release said.

Woodman signed the Buffett-Gates pledge to give away half his wealth, and CNBC was told that he had wanted to give those funds away sooner, but the source said the decision was for administrative purposes.

The Woodmans said in the release that they have personally contributed the shares from their own holdings toward the foundation, effective Friday.

Read MoreRead this before you buy GoPro: Options trader

GoPro shares fell below $80 on Thursday, after reaching a high above $90 earlier in the week. The stock has been red-hot since its IPO earlier this year, more than tripling from the offering price of $24 in June.

That has also attracted the interest of short sellers, who have been aggressively borrowing the stock to sell it in a bet that prices will fall. More than 41 percent of the company's stock is sold short, making it one of the most-shorted stocks in the entire market.

GoPro said in a statement to CNBC, "We are extremely proud of Nick and Jill Woodman for establishing a $500 million foundation for charitable giving."

It also added, "Any activity by the charity related to these shares would have to be accompanied by a public filing."

On CNBC's "Halftime Report" on Thursday several contributors weighed in.

OptionMonster's Jon Najarian noted that GoPro options had been trading 10,000 puts a day in August but spiked just this week, hitting 120,000 puts on Monday and 140,000 puts on Tuesday.

"Who knew that this thing was coming unlocked? Who knew that they were going to put another 20 percent on to the float of this stock? JPMorgan," he said. "Well, those would be the first guys I'd want to see and say, 'Did you guys buy this stock?' 'Did you short it?' Either of those two things. These puts indicate people know. They made an awful lot of money on this downward move."

Najarian likened it to buying a photocopier from a law firm and finding documents about an impending deal, speculating that someone had inside information.

"They had tomorrow's newspaper today," he said. "They knew that they were going to bring 20-some-odd extra percent to the float. And that's why the shares are down so hard today."

Yahoo Finance Senior Editor Mike Santoli said that he wouldn't have wanted to see this news if he had been a shareholder.

"It seems like they were looking for a way to get liquid through a back door and do it through the foundation," he said. "But, look, I have a hard time summoning a lot of tears for the people who bought in this last little spurt higher."

Noting that "over 80 million shares—the entire company" had changed hands in the past week, Santoli added that buyers "weren't really looking at the details of corporate governance and the compact between an underwriter and the insiders and everything else."

"This thing was a pass-the-crack-pipe type of stock in the last week here," he added.

Santoli said he wasn't all that worked up about the development, which could be short term. "But it just really tells you both what kind of people run the company, what their priorities seem to be and just how dependent it was on a very scarce float."

—Additional reporting by CNBC's Bruno J. Navarro and Kayla Tausche.