The evidence that this is forced liquidation
The heavy selling in equities to me look like liquidation of longs to cover loses in shorts. The $GME squeeze alone might have caused more than $30 billion in losses. There are squeezes on other heavily-shorted stocks as well.
When there's a fund liquidating, word gets out and everyone tries to front run it.
The timing -- right at the open -- is also curious and looks like liquidation. We saw a similar episode earlier in the week and into the close as well.
Separately, regulators are getting all kinds of calls about market manipulation and meme stocks but a consistent problem lately is brokerages going down. This is 2021, not 2001. I don't think kindly to brokerages repeatedly failing when people are trying to move money. They only need to work for 6.5 hours per day and this consistent poor form is problematic.
Meanwhile, at some point price action can be its own story and force fund liquidation can turn an entire market; especially if Powell gives everyone a reason to sell.