* GameStop (NYSE:GME) down about 5% in morning trading, AMC gains 3.8%
* GameStop stock down 80% from last week's peak until Tuesday
* Yellen calls top regulator meeting on market volatility (Adds details of other Reddit stocks, U.S. equity option volumes)
By Tom Westbrook and Sagarika Jaisinghani
Feb 3 (Reuters) - A social media-driven trading frenzy cooled further on Wednesday as U.S. Treasury Secretary Janet Yellen called a meeting of top officials that could result in tougher markets regulation for hedge funds, small investors and stockbrokers.
Mass buying by amateur traders over the past two weeks has driven wild price gyrations in companies that U.S. fund managers had bet against, including videogame retailer GameStop GME.N and cinema operator AMC Entertainment AMC.N .
GameStop's U.S.-listed shares, which scaled as high as $483 last week, fueled by posts on the popular Reddit forum WallStreetBets, deflated this week to $90 as fee-free broker apps including Robinhood imposed buying curbs.
They fell another 5% on Wednesday, while shares of AMC were up 3.8% following a drop of 41% a day earlier. GameStop's Frankfurt-listed shares GMEa.F continued to decline, falling 36% by 1510 GMT.
Silver XAG= , which briefly surged on Monday as small traders bought up the metal, steadied about 10% below its recent peak. GOL/
"The unwind is obvious," said Oriano Lizza, premium sales trader at brokerage CMC Markets in Singapore, adding that it would be easy for nimble small investors to regroup and target fresh companies.
"I think from a regulatory standpoint, the concern is that they could continue to do this," he said.
The head of the U.S. Securities and Exchange Commission, which regulates markets, will meet with Yellen and the heads of the Federal Reserve and the Commodity Futures Trading Commission, possibly as soon as Thursday, a Treasury official told Reuters. has asked to discuss recent volatility and whether trade has been consistent with fair and efficient markets. was not clear if a meeting could result in action, but experts expect focus to also fall on the ever-larger role played by non-bank firms such as hedge funds in financial markets, while small traders are bracing for a showdown. boss fight. It's happening tomorrow with Yellen, SEC and Federal Reserve," read one Wednesday post on Reddit. "They are either going to try and stop the party or they are looking for money to pay us and not crash everything at the same time."
Robinhood said on Wednesday it was allowing buying of fractional shares in GameStop and AMC, five days after restricting the practice that has encouraged smaller traders by reducing the size of the amount they need to invest. MANIA
Small investors' participation in stock markets has exploded over the past year, but the gambling sparked by a combination of pandemic lockdowns, volatility and stimulus payments comes with high risks that regulators may want to quell.
Still, there have been no clear signals on what form any official action could take, with potential targets ranging from retail brokers' capital requirements to questioning the fee-free brokerage model that has encouraged much of the trade.
The benchmark S&P 500 .SPX , meanwhile, has continued to grind higher this week and the CBOE volatility index .VIX has fallen for three straight days as analysts said the Reddit action appeared to be constrained to a handful of stocks rather than spilling over to the broader U.S. stock market. .N
"There isn't much of a worry that this is a signal that could destabilize the whole system," said Simona Gambarini, markets economist at Capital Economics.
"If monetary and fiscal policy remains supportive and the economy recovers from the pandemic with the help of vaccines then equities could go up quite a bit more."
Other so-called "meme stocks" caught up in the Reddit rally rose on Wednesday, with headphone maker Koss Corp KOSS.O and home furnishing retailer Bed Bath & Beyond BBBY.O rising 27% and 2.2%, respectively. BlackBerry Ltd's U.S.-listed shares BB.N were down 3.2% following a 21% slide a day earlier.
GameStop, AMC, BlackBerry and Koss did not respond to Reuters requests for comment. Bed Bath & Beyond declined to comment.
PUTS ON
The retail trading boom drove volumes in U.S. equity options to a record monthly high in January and some investors may now be turning to "put options", which are often used to protect against losses or position for declines in a stock's price, as an alternative to shorting the stock, analysts say. to borrow GameStop shares has subsided significantly in recent weeks but remains high overall, making it relatively expensive to short the stock. broker Robinhood has also come under pressure and has scrambled to raise more than $3 billion in a week as it races to meet funding needs stemming from the trading boom. further relaxed some of its restrictions on trade on Tuesday, increasing buying limits on GameStop stock from 20 shares to 100 shares. enthusiasm for this unique situation is waning but we'll continue to see people focused on what the retail investor as a flash mob can accomplish," said James Gellert, CEO of RapidRatings, which assesses the financial health of companies.
<^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EXPLAINER-How retail traders squeezed Wall Street for bets against GameStop
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