(Bloomberg) -- The U.S. Securities and Exchange Commission is keeping a close eye on stocks that have surged to extraordinary heights during the recent bouts of wild trading but has seen no evidence that the broader market is under threat, Allison Herren Lee, the regulator’s acting chair said Monday.

“We haven’t seen anything to indicate anything that suggests it would bring down the market,” Lee told NPR in an interview.

Lee didn’t name the individual stocks that the SEC is monitoring, though those that have captured the attention of Wall Street and Washington include GameStop Corp. and AMC Entertainment Holdings Inc. GameStop in particular has prompted a frenzy, rising more than a 1,000 per cent since the start of the year. The House Financial Services Committee has scheduled a Feb. 18 hearing on the tumult, which will shine a spotlight on how an army of retail investors armed with Robinhood Markets accounts have hyped up stocks on social media.

“When we see stock prices depart so wildly from fundamental valuations, we know there is a chance that people are going to get hurt,” Lee said. “We want people to know that there are risks involved here.”

Determining if anyone tried to take advantage of the situation by manipulating share prices is a priority, Lee added. One challenge is that successful fraud cases often hinge on the SEC showing that traders spread false information to dupe others into buying or selling stocks. The SEC hasn’t accused those talking up companies on Reddit of doing that.

“This one has a little bit of a different spin to it, it’s going to be a little more challenging because of the nature of it,” Lee said. “But our enforcement division will rise to that challenge and they are working around the clock right now to figure that out.”

The SEC is also looking into the conduct of brokers and the role that short-selling -- or, betting against stocks -- might have played in the recent events.

President Joe Biden has nominated Gary Gensler to lead the SEC, but he has yet to be confirmed by the Senate.