High-speed trading to blame for plunge, says NYSE
“We have a market that responds in milliseconds, but the humans monitoring respond in minutes, and unfortunately billions of dollars of damage can occur in the meantime,” said James Angel, a professor of finance at the McDonough School of Business at Georgetown University.
The glitch that sent markets tumbling Thursday was years in the making, driven by the rise of computers that transformed stock trading more in the last 20 years than in the previous 200, Nelson D. Schwartz and Louise Story report in The New York Times.
The old system of floor traders matching buyers and sellers has been replaced by machines that process trades automatically, speeding the flow of buy and sell orders but also sometimes facilitating the kind of unexplained volatility that roiled markets Thursday.
Computerized trades sent to electronic networks turned an orderly stock market decline into a rout, according to Larry Leibowitz, the chief operating officer of NYSE Euronext. Nasdaq OMX Group Inc. canceled trades in 286 securities that rose or fell 60 percent or more.
While the first half of the Dow Jones Industrial Average’s 998.5-point intraday plunge probably reflected normal trading, the selloff snowballed because of orders sent to venues with no investors willing to match them, Leibowitz said in an interview on Bloomberg Television.
“If you look at the charts you can see fairly clearly where the trades came in,” he said from New York. “It’s that V-shaped drop where it came down and snapped right back up. You had some very high-cap stocks trading down 50 percent or large percentages in a split-instant because there really was no liquidity in electronic markets.”
In recent years, what is known as high-frequency trading—rapid automated buying and selling— has taken off and now accounts for 50 to 75 percent of daily trading volume. At the same time, new electronic exchanges have taken over much of the volume that used to be handled by the New York Stock Exchange.
In fact, more than 60 percent of trading in stocks listed on the New York Stock Exchange takes place on separate computerized exchanges.
Many questions were left unanswered even hours after the end of the trading day. Who or what was the culprit? Why did markets spin out of control so rapidly? What needs to be done to prevent this from happening again?