Today's reverse engineered HFT algo strategy: if price drops more than x% in a millisecond, then enter order y% below bid, else pull all bids, especially when price is 90% below most recent NBBO posted a mere second earlier. Which is precisely what happened to Progress Energy (PGN), which dropped from $44 to $4 in less than second, but not in quantized fashion (i.e. fat finger), but in a gradual, than exponentially accelerating manner, as an algo took out all the bids. We can't wait for this week's 21st sequential outflow from equity funds: luckily investors are now all too aware that holding a stock, any stock, is dangerous to one's sanity, not to mention stop loss orders. And where the hell was the circuit breaker on this one? The market is and continues to be a miserable joke, especially courtesy of Nasdaq and the 160 trades in PGN that occurred at ridiculous, HFT-exaggerated prices. And of course, all those lucky fools who bought the stock at a 90% discount are about to be DKed, because it is Nasdaq's prerogative to protect its HFT paying clients, and not investors.
And here is the stepwise drop from $44 to $4, with no circuit breakers being activated. Total and absolute farce. In China someone would have taken a bullet for this. Only in America do the regumalators demand greater budgets, and year end bonuses, to continue their worthless shitjobs.