Does the whale digger really sold all his CLAMs yesterday?
If you believe what he says, yes. Beyond that it is impossible to know.
No more dumps?
Other people, including whoever supposedly bought his 100 BTC worth of CLAMs, might dump.
The stake weight on the network has gone up by about 200K CLAMs, so someone is staking coins that weren't be staked yesterday. That is unambiguous.