Over the past few days, we have carefully tried to put together the pieces of the "liquidation puzzle", to find out i) just who is selling, whether machines or people or some combination of both, and ii) is there more selling to go? Readers can catch up on some of our most recent articles on the topic below:

Gamma Trapdoor Opens: Markets Brace For "Shock Down" As Dealers Puke

What's Behind Today's Market Plunge? A Stunned Wall Street Responds

Morgan Stanley: If We Close Below 3,235, Systematic Selling Will Become "Self-Fulfilling"

The $60 Billion Puke: Here Comes The Systematic Selling... And Watch The Russell 2000

CTAs Begin Selling

Nomura: Investors Are Finally Considering A "Previously Unthinkable Scenario"

And while, as often happens with such opaque market positioning and flow topics, no clear answer has emerged, with contradictory and confusing evidence pointing to the recent sharp drop in dealer gamma, the triggering of CTA deleveraging, the unwind of record net long SPX speculative positions, forced selling by quant/systematic (vol targeting, risk parity) funds as well as liquidations by discretionary hedge funds operated by carbon-based traders.