Quote from JSSPMK:
Governments say what people need to hear. You said it yourself about HFTs ability to move market is limited & what happened on May 6th was liquidity vacuum. I posted on another forum at the time that weekly TICK did look anything but bullish & that caution had to be used if going long SIFs at that time. Similar picture is present now where NDX is at neckline of a massive inversed H&S, but weekly TICK suggests that buying has been subsiding as it's MACD has been falling towards the centreline & now is below it. Jim Rogers has been saying for a while now that he is not buying equities & the way market dropped on May 6th points to lack of confidence when market is weakening.
Nobody rings the bells when at the top 
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Because HFT trading represents half of es daily volume (average es daily vol $140 billion), that is enough to triggered large institutionals tight stop and clearing firms emergency stops (loss limit).
Remember, HFT is run by a prop firms, but they called themselves HFT Firms. These large institutionals have a new competitors in the market that barely existed 10 years ago.
HFT firms recruit high tech engineers from MIT, yale, havard, stanford, or any ivy league high tech universities. these MIT engineers are like god. they create a software (algor) and they are paid handsome income while the HFT owners are salemen looking to funds the trade from private institutionals like banks (citibank, chase, bac) worldwide and not only in the U.S. They will even have shieks pour money in.
Of the $140 billion es daily volume, retail traders only represent 1%. I think that is why emg trades $100K per contract without stop.
The retail traders are the sheep and the big players are the wolves. "The power-hungry 'wolves' were hit hardest by a defeat, whereas the 'sheep' couldn't care less about being beaten."
...not that I care one way or the other..