0 of 0

Wednesday's computer-related problems on the New York Stock Exchange that halted trading for more than three hours was not a one-off. Over the years, stock exchange failures have been attributed to everything from technical glitches to a stray squirrel.

Here are some recent incidents:

Aug. 22, 2013: Technical Glitch at the Nasdaq

Trading was halted for more than three hours. Nasdaq blamed the problem on the system that handles stock quotes.

Aug. 20, 2013: Goldman Glitch

Just three days earlier, a programming error caused Goldman Sachs to place erroneous orders for stock options. As Bloomberg noted at the time: "An internal system that Goldman Sachs uses to help prepare to meet market demand for equity options inadvertently produced orders with inaccurate price limits and sent them to exchanges." Estimates of the loss ranged from tens of millionsto $100 million. Goldman later paid $7 million to settle the regulatory claims.

Aug. 1, 2012: Knight Capital

This computer glitch caused the firm to buy a great number of stocks, a mistake that cost the firm $440 million, greater than the company's second-quarter revenues of $289 million that year. The New York Times estimated at the time that the error cost Knight $10 million a minute.

May 18, 2012: The Facebook IPO

Facebook's much-vaunted initial public offering was delayed because of a Nasdaq trading problem. The exchange's chairman later apologized and agreed to pay a $10 million penalty for the way it handled the IPO.

May 6, 2010: The 'Flash Crash'

The "flash crash" wiped about 600 points from the Dow Jones industrial average in mere minutes, leading to about an $800 billion loss; the market recovered almost as quickly. (You can read a timelineof what happened that day from The Wall Street Journal). The crash was at first blamed on computer trading by a large mutual fund company, but earlier this year, U.S. prosecutors charged a British man who they said contributed to the crash.

And — now for that squirrel we mentioned at the top:

As The New York Times reported Dec. 10, 1987:

"An adventurous squirrel touched off a power failure in Trumbull, Conn., that shut down the National Association of Securities Dealers' automatic quotation service for 82 minutes yesterday."

Copyright 2016 NPR. To see more, visit http://www.npr.org/.