High speed trading fueled Twitter flash crash

  @maureenmfarrell April 24, 2013: 10:05 AM ET
Dow flash crash

The Dow dropped more than 140 points Tuesday.


One scary -- and false -- tweet, and the Dow quickly plunged 140 points, or roughly 1%. Many are pointing fingers at high speed trading by computers for the swift decline.

The Dow quickly bounced back. The sharp sell-off highlights just how disruptive computer-driven high-frequency trading can be.

The S&P 500 lost $121 billion of its value within minutes.

High-speed computer trading accounts for roughly 50% of all trading. That's down slightly from a few years ago, but traders on the ground say it feels more dominant.

And mini flash crashes have become an all too familiar daily occurrence.

"This shows the Achilles' heel of a market structure that has high-frequency trading as its backbone," said Sal Arnuk, co-head of trading at Themis Trading.

Related: False tweet roils markets

Traders and analysts say that at the first sign of crisis (and sometimes in the absence of a crisis), high-frequency traders pull out of the market, leaving a void of buyers and sellers.

In fact, liquidity dried up even faster after the false tweet Tuesday than it had during the infamous Flash Crash of 2010.

Eric Hunsader, the founder of Nanex, a firm that tracks trading behavior. said Tuesday's market reaction shows that trading has become even faster in recent years.

Related: Mini flash crashes: A dozen a day

"One tweet can do more damage to our market's liquidity than the flash crash," said Hunsader. Certain trading pools were overloaded, and trades weren't reported for four minutes, he added.

Within the past year and a half, disruptions in the market marred the IPOs of the BATS exchange and Facebook.

Just Monday, Google (GOOG, Fortune 500) had an inexplicable flash crash. It only lasted a few seconds but still signals the fragility of markets in a high-speed trading world.

The SEC, Nasdaq and NYSE all declined to comment on Tuesday's flash crash.

A spokesperson for BATS called the drop a "non-issue for the trading community" and said the exchange had not received any calls from customers. To top of page

Join the Conversation
Sponsored by
Index Last Change % Change
Dow 16,424.85 162.29 1.00%
Nasdaq 4,086.23 52.07 1.29%
S&P 500 1,862.31 19.33 1.05%
Treasuries 2.64 0.01 0.34%
Data as of 7:10pm ET
Company Price Change % Change
Bank of America Corp... 16.13 -0.26 -1.59%
Facebook Inc 59.72 0.63 1.07%
Yahoo! Inc 36.35 2.14 6.26%
Intel Corp 26.93 0.16 0.60%
Alcoa Inc 13.42 0.37 2.84%
Data as of 4:02pm ET
Overnight Avg Rate Latest Change Last Week
30 yr fixed4.41%4.44%
15 yr fixed3.33%3.31%
5/1 ARM3.34%3.55%
30 yr refi4.39%4.41%
15 yr refi3.31%3.30%
View rates in your area
Find personalized rates:
Rate data provided
by Bankrate.com
Market indexes are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer LIBOR Warning: Neither BBA Enterprises Limited, nor the BBA LIBOR Contributor Banks, nor Reuters, can be held liable for any irregularity or inaccuracy of BBA LIBOR. Disclaimer. Morningstar: © 2014 Morningstar, Inc. All Rights Reserved. Disclaimer The Dow Jones IndexesSM are proprietary to and distributed by Dow Jones & Company, Inc. and have been licensed for use. All content of the Dow Jones IndexesSM © 2014 is proprietary to Dow Jones & Company, Inc. Chicago Mercantile Association. The market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. FactSet Research Systems Inc. 2014. All rights reserved. Most stock quote data provided by BATS.