it is. See, an OTC desk for example who just sold a bunch of BTC to an institution is "short" Bitcoin. They want to balance their book before the markets close. The same goes if they're long Bitcoin by having more BTC on their book than they should have dollar. As for brokers, they're unlikely to leave open positions on the markets unattended. Add their end-of-year reporting to the mix and you got the full picture.

It's the same every year and one reason why I stopped stealing sats for a few days. I'll get back to that in the new year once everyone else returns to their trading desks.