Facebook shares jumped on Wednesday as 800 million new shares became eligible for sale as the latest in a series of lockups expired. Shares closed at $22.36.

The New York Times reports that Andreesen Horowitz, one of the company’s biggest investors, sold over 4.6 million shares within an hour of close. Most of these shares were reportedly the firm’s shares in Instagram, which Facebook recently acquired. The firm still has 3.6 million shares in Facebook.

Those shares that became eligible for sale includes those held by the Winklevoss Twins. TMZ reports that they’re holding onto their shares (some of them at least):

The twins own close to 6 million shares of FB stock — now worth around $125 mil — and they were free to trade their stock starting today. But we’ve learned … they will only unload $1 million worth of stock, which they will use as seed money to fund their new venture — an e-commerce website called Hukkster.com. The website tracks your favorite products and alerts you when they go on sale.

The Winklevii are investing in a new online shopping startup called Hukkster. More on that here.

As of the time of this writing, shares are trading at $21.97. At the time of the IPO, Facebook shares opened at $38.

Image: Cameron Winklevoss’ Facebook page