Quote from bone:
The reports from the SEC and the CME all mention how liquidity from HFT programs dried up under stress and then amplified the price swings when it did finally show up.
All in all, Âgwhat happened is best described in
terms of two liquidity crisesÂ]Â]one at the broad index level in the EÂ]Mini, the other with respect to individual stocks," with the caution that high trading volume "is not necessarily a reliable indicator of market liquidity." The phrase, "liquidity had virtually evaporated" is used in different contexts within the report.
http://www.itg.com/news_events/insights/In_Domowitz_101310.pdf
Well... I don't expect that HFTs would step in front of the downtrend. The fact of the matter is that lots of entities stopped bidding including HFTs.
How do these people define liquidity anyway...?
Liquidity is usually when you place an order on the BID/OFFER and wait for it to get filled. ECNs pay you a credit for placing orders either on the BID/OFFER but you pay a fee for removing liquidity. That is if you want to buy and the spread is 10.01 - 10.02 and you hit let's say ARCA at 10.02 you pay the fee for hitting the OFFER...
So HFTs really do both... Sometimes they add liquidity by staying on the BID/OFFER and get payed a credit when their order gets filled and sometimes they hit the BID/OFFER and pay a fee. They're just an automated market player that's all. For the most part HFTs don't make money on every trade. Just because you have an algo. doesn't actually mean your algo. is a winner...
So the fact that HFTs stayed away from the BID during a downturn doesn't mean that they're all bad... They were just being cautious. Even if they were selling during the downturn they weren't doing anything wrong. It is a free market and you have the right to go short whenever you feel like it. Afterall, long term investors and institutions also stayed away from the BID but no one is blaming them.
WORSE... Paulson (Secretary of the Treasury) the guy who was supposed to fix the mess went short and made 1 billion dollars from that short trade on the market and he was supposed to be the guy that was supposed to stop the market from falling.
Riiiight... Blame the evil short term "penny jockeys" for taking the "liquidity".
That Ian Domowitz report that you provided is really inconclusive...
"The trigger is a small part of the story, however, and we should keep in mind that a trigger is not a cause."
Yeah that's true, the fact that an algo. sold 35000 contracts isn't proof that the algos. are bad. In fact, a large firm could have done the exact same thing without using algos. ... These big orders by big traders used to happen before as well... Nothing new here.
"Performance in terms of the price slippage of any algorithm deteriorates with the
combination of increased liquidity demand and higher volatility."
Indeed... So algos. get screwed just like anyone else when the market changes...
I don't see what the big deal is...
