All this means is that crypto miners who are in the F2pool (which is massive) are moving their coins from their F2pool wallets to other wallets. It doesn't necessarily mean they are selling.
My guess is that some are selling and some are just securing their coins in cold wallets because the rise in BTC price also means a rise in liability.
I mine bitcoin and litecoin and my miners are in the nicehash pool. I move my coins out of my nicehash wallet about every 10 days.