The Whales and dolphins are already selling. For example Heiditravels announced in a post that she'd sold all her SteemDollars to fund another trip. She probably dumped them all at once and crashed through the buy orders.
If the big guys are dumping, the small guy should too, otherwise you end up a bagholder.
RE: Why Whales and Dolphins will not Sell off and why you should not too