He owns a 3.4% stake in the company: 2.36 million shares that now are worth more than $800 million, based on premarket action Friday.
Sherman hasn't made any media appearances this week. He was quoted in a press release about the company winning top marks as a place for LGBTQ workplace equality. But he's been mum about the stock's breakneck volatility.
Meanwhile Ryan Cohen, the Chewy (CHWY) founder who is now on GameStop's board, runs a fund that owns nearly 13% of GameStop -- a stake now worth about $3 billion that makes it the second biggest investor in the company.
Big money managers Fidelity, BlackRock, Vanguard and Susquehanna are the other top five shareholders.
And Donald Foss, a retired billionaire who is the founder of subprime auto lender Credit Acceptance Corp (CACC), bought a 5% stake in GameStop last year that's now worth $1.2 billion.