To be clear, I'm not claiming Citadel created double digit drops in SK Hynix / Samsung. I am saying that as market vol hits, vol traders might choose to make it worse. And when word hits the street someone has a liquidity position, prop traders WILL come and pressure. SA's filings were clear how concentrated they were, and this was known. In this case, Citadel (hedge fund) bought, while I imagine Citadel Securities would have been doing this (speculated upon) trading. We'll know more when the filings come out though. I'll be curious what of the portfolio they kept and what they worked / rolled in the market