(Reuters) - Retail darlings GameStop ( GME ) and AMC continued their slide into premarket trading on Thursday, as the euphoria over the return of "Roaring Kitty", who was the central figure in 2021 meme stock rally, fizzles out.

Shares of the struggling videogame retailer GameStop ( GME ) fell 16% to $33 after jumping as much as $64.83 so far this week. Theater chain AMC shed 13% following an 88% gain since Friday's close.

Despite the losses on Wednesday, the two companies were among the top three most-traded shares by retail investors during the session, data from J.P.Morgan showed, a position they have held every day this week.

The sharp surge in the shares began after a series of posts from Keith Gill's X account "Roaring Kitty", whose bullish posts on GameStop ( GME ) was a reason for the 2021 meme stocks frenzy.

But unlike 2021 when Reddit users banded together to target highly shorted stocks that burnt bearish hedge funds, this time retail and institutional investors were part of the meme stock mania, Vanda Research, which tracks retail investor flows, said.

Since his first post on Sunday, Gill has put out dozens of cryptic movies clips a day on X.com. He did not respond to a Reuters request for comment on what the posts mean and whether he planned on making his investments public again.

Former U.S. SEC Chair Jay Clayton told CNBC on Wednesday the posts have triggered "a wave of euphoric and speculative buying in the retail (trading) community which is never a good thing", adding that it was not illegal to say "I like a stock".

Retail purchases of GameStop ( GME ) eased to $5.7 million in the previous session from $15.9 million on Tuesday, which was the highest this year, Vanda data showed.

Similarly, for AMC, daily retail inflows dropped to $7.7 million on Wednesday from $51 million in the previous day.

Other highly shorted stocks that caught a bid this week also fell on Thursday. Tupperware dropped 7% to $1.68, while U.S. listed BlackBerry shed 4.6%.

(Reporting by Medha Singh in Bengaluru; Editing by Arun Koyyur)