Whales are transferring their funds into the exchange to buy more before the next ATH hits again, that's what I think.
I doubt that a 'real whale' will do that, because it attracts so much attention, would rather do OTC. If there's one thing that the whale should do, it should be the opposite, not putting all their big btc in an exchange.
This is a little alarming but nothing to worry about but this gives an insight that there is a possible surprising thing to happen in the market a few days from now. We have to still calm down and have to prepare for what happens in the coming days. For now, it was a need to monitor the progress of this movement since we don't know where it comes from and what is the real purpose of that.
We are still not sure about it, as others have pointed out, there's not way to pinpoint whether it's really a whales or an exchange or maybe some crpyto bookies moving their stash somewhere safe. So I doubt that there's something big gonna happen in the market in the next coming days. If there is, then it's just coincidence.