The stock market is in the thick of another meme stock frenzy, sparked by Sunday night's online return of one of the key figures of the 2020 and 2021 craze that sent GameStop (GME) shares to record highs. GameStop has been one of the biggest winners of the frenzy this week, along with AMC Entertainment (AMC). Those and other meme stocks have shot higher following the online return Sunday of one of the prominent drivers of the earlier meme craze. Keith Gill, known by his online persona of "Roaring Kitty," p ...