The Fourteenth Banker writes today:
In the stock market, program trading dominates volume. I heard recently that 70% of trade positions are held for an average of 11 seconds.
As the New York Times dealbook noted in May:
These are short-term bets. Very short. The founder of Tradebot, in Kansas City, Mo., told students in 2008 that his firm typically held stocks for 11 seconds. Tradebot, one of the biggest high-frequency traders around, had not had a losing day in four years, he said
Similarly, FT's Martin Wheatley pointed out last month:
I know of one HFT firm operated out of the west coast of the US that boasts its average holding period for US equities is 11 seconds
And market analyst Peter Cohan writes at AOL's Daily Finance:
70% of trading volume on the major exchanges is conducted by high-frequency traders who hold a stock for an average of 11 seconds.
The fact that the vast majority of stock market trades are held for 11 seconds shows that the stock market is not a real market with real traders governed by the law of supply and demand, and with no real price discovery.
But as Tyler Durden points out, alot can happen in 11 seconds when the players are high-powered computers:
07-29-10 BATS "Flag Repeater". 15,000 quotes in 11 seconds, dropping the ASK price 1 penny each quote from $9.36 to $8.58 and back up again.