Today is the debut of Facebook on Nasdaq, despite the hype before Friday, the price fell back to IPO price in the end.

As of 4:15pm EDT, it’s just $38.00 – the price set on Thursday afternoon. But Facebook breaks another record: the volume. It traded 567 million shares by 4:15pm, the most ever for a stock debut in U.S. history.

The prior record holder was General Motor, which traded 458 million shares on the day of IPO in 2010.

About 100 million shares trading happened in the few minutes after the stock opened.