May 15 (Reuters) - Shares of GameStop and AMC soared in premarket trading on Wednesday, continuing this week's rally which began after "Roaring Kitty" Keith Gill, a central figure behind the 2021 meme stock frenzy, resurfaced on social media.

"Roaring Kitty", the online persona of Gill, shared a clip from the movie "Braveheart" at 8 p.m. ET on social media platform X on Tuesday with the word "GameStop" flashing on the screen as Mel Gibson, playing William Wallace, screams "freedom".

It is the first time Gill has mentioned a company name this week, after his return to X following a three-year gap set off a rally in meme stocks reminiscent of 2021 retail trading frenzy.

His YouTube streams and a string of posts by Reddit username DeepF***ingValue, had helped attract a flood of retail cash into GameStop in 2021, burning hedge funds who had bet against the company.

Cinema chain AMC soared 18% on Wednesday, after rising 135% in the past two sessions, while video game retailer Gamestop jumped 19% after hitting its highest level since June 2021 on Tuesday.

The posts hinted at Gill beginning to get back in action, although it was not immediately clear what he would do next. Gill did not respond to Reuters' request for a comment.

Roaring Kitty's return is "sparking big talk in chat rooms about what he may have up his sleeve," said Susannah Streeter, head of money and markets at Hargreaves Lansdown.

"This is a trend driven by entertainment rather than company fundamentals.. stocks which rocket up on pure speculation, tend to drop back down to earth very quickly." (Reporting by Alun John and Medha Singh; Editing by Amanda Cooper and Varun H K)