There's a big amount of tether converted back to bitcoin few days ago after reaching the price to $13k the price drop and looks like bitcoin is exchange back tether and exchange to other stable coin like USDC and TUSD this is just what I notice yesterday.

So I think it's just a normal and not handle by whales most of them are trader's I'm sure because I'm one of who buy bitcoin and traded back to tether and buy again few hours ago just to get the opportunity to make profit while the price is high.