NEW YORK (Reuters) – Shares of Snap Inc (SNAP.N), owner of the Snapchat messaging app, fell 3 percent in premarket trading on Monday as a share lockup ended, allowing for sales by early investors and pushing it further below its March initial public offering price.

Starting on Monday and extending into August, early investors, employees and other insiders will be able to sell shares for the first time since its $3.4 billion IPO, the third-largest for a U.S. technology company.

As of Monday, investors including Lightspeed Venture Partners will be able to sell up to 400 million shares, with employees owning another 782 million allowed to start selling on Aug. 14, four days after Snap reports results, JPMorgan analyst Doug Anmuth said in a recent note.

Snap’s shares were down 3 percent at $13.40 in trading before the U.S. market opening, putting it 21 percent below its $17 IPO price. It hit a low of $13.14 on Thursday.

The company’s stock has been dragged lower by investor concerns about user growth and waning confidence in its ability to eventually turn a profit.