Albeit a minor one. We’ve seen huge ones for announcements. Near doubling in price then big dumps a couple years ago.
The whales were more likely worried about BTC then to try and pump a under hyped alpha release
The forum made plenty of buzz for weeks and the announcement in the previous dev update saw the price rise a little IIRC and the pump-n-dumper had probably bought prior to that so the dump as little as it was made them some profit.
Its a network that will remain running even when later testnets are running. Its for developers to have a stable platform to develop against.
In my opinion it will be alpha 4 and later that will see more of this. Should have vaults at home in alpha 4.