Nope. It won't work. By the time you realize which cryptocurrencies the whales are pumping or dumping, it's too late. The only way to get a piece of their action is to become a whale insider yourself.
Shitcoins obviously won't work, pump and dump will happen too quickly with them.
What if you monitor established currencies like BTC?
Say we trade BTC, we have to buy low. We can try waiting for another bloodbath, then at the very low, there's a possibility whales would appear and trigger trend reversal, and you may observe it by watching volumes.
Just a theory though. Gonna have to wait to test it.