Saying that bluffing is not allowed is disingenuous. Why, then, are sellers allowed to break up big blocks of stocks into smaller orders to avoid triggering algorithms in the market? How is that not bluffing. "I have 1M shares to sell, but if I do that, I'm going to take a bath. But if I trickle them in, break them up, etc..." - what makes one strategy, and the other a bluff?