Why are we assuming that this was a whale and not simply sell pressure that was unsupported by buying action since the fiat system is closed down for the weekend?
Can't you just believe that people are coming in droves? One such came in last month. Now everybody is waiting, counting their coins. If no drove comes, everybody sells, newcomers and old ones alike.
I know the magnitude of droves grows on average 1140% per year. It's a lot, but you cannot draw the conclusion that each month the USD flow is bigger than last month. Because it isn't.