So either it’s a coincidence that it happened the day prior or there was some leak. Someone knew about this, most likely someone at coinbase or the government and leaked it and everyone shorted.
But when the news came out, it already bottomed. So it’s strange.
Maybe this is a little leak from an insider because if there is no news of this then I don't think it is possible that the price has dropped so much even though the price has dropped this news came.
Remember that news of leaks will always exist sometimes when people already know then they will take advantage by going short, it was worth it a few months ago where one Cointelegraph went short and profited from it.
We don't know what actually happened but for sure, they gained a lot from this sell-off, if they really did sell some of it. High likely, they did as we have seen the price declined and was also wondering at that time. But here we are, heading back to 70k again. That means, this sell-off showed that even multi-million or billion-dollar sell-off is involved, it won't cripple the btc market.