Facebook hits new low as IPO 'lock-up' ends

Facebook's stock plunged to a new low Thursday as some of the social networking leader's early backers got their first chance to sell their shares since the company's initial public offering went awry.

Analysts interpreted the unusually high trading volume as a clear sign that at least a few of the insiders were seizing on a fresh selling opportunity. That is stirring a debate over whether they're simply locking in long-awaited gains on investments made many years ago or bailing out of a company that has lost its luster.

A breakdown on just how many major Facebook Inc. shareholders sold their stock probably won't be available until next week at the earliest.

The information is important "because if you are an investor who has been sitting on the sidelines waiting for a good time to buy the stock, you might decide to stay on the sidelines for a little longer after seeing which insiders decided to sell their stock," CapStone analyst Rory Maher said.

All told, investors who owned a combined 271 million Facebook shares could have sold their holdings Thursday with the expiration of a ban known as a lock-up period.

The shares have plunged by nearly 50 percent since its initial offering three months ago amid concerns about whether Facebook is a passing fancy and worries about whether it will be able to sell more advertising on mobile devices.

Facebook' stock traded as low as $19.69 before bouncing back slightly. The shares closed at $19.87, down $1.33, or more than 6 percent.