The Securities and Exchange Commission indicated after the market close Friday that it would review trading issues on the Nasdaq related to Facebook’s initial public offering.
There were reports that some confirmations about order execution were late in coming from the exchange when Facebook shares began to trade earlier in the day.
“As is our practice, staff will review the incident with Nasdaq to determine its cause, and steps that will be taken to address it,” a spokesman for the regulator told CNBC when asked about the complaints.
There were 2.58 billion shares traded at the Nasdaq Friday — the highest level since Dec. 16. Of that, about 573 million shares were Facebook trades, accounting for over 22 percent of the volume.
— CNBC's Bob Pisani contributed to this report.