That volatility triggered a trading halt on Nasdaq OMX.
Trading resumed five minutes later and returned close to the price it was at before the halt. Nasdaq said the five-minute trading halt worked exactly as it was designed for price changes of 10 percent. It said no trades were cancelled.
Symantec spokesman, Chris Paden called the trading activity "unusual."
"Some entity filed a trade without placing limits on the price," he said. That, he said, caused the market to buy at lower and lower prices until circuit breakers kicked in.
"(It) wasn't an erroneous trade, it was a trade that was filed erroneously," he said. A seller might have avoided that by entering a "limit" order as opposed to a "market" order.
Comments on Twitter were fast and to the point.
Eric Hunsader of Nanex tweeted, "I think $SYMC just took the crown for fastest imploding big cap stock. #HFT"
@StockTwits simply posted the chart that illustrated the "tick that caused it to halt". (Click here to see the chart)
And Sal Arnuk of Themis Trading put it this way: "$SYMC = Charlie Brown Lucy Football Yank. "
This is the latest in a series of unusual "flash moves" that have whipsawed individual stocks.
(Read More: Algorithms Replacing Wall Street Analysts, Investors)
Birinyi Associates and Nanex pointed out odd trading in Google about a week ago.
The entire stock market made a "flash move" after the Associated Press was hacked just last week, and someone tweeted a fake headline on its account about an explosion at the White House.
(Read More: Credibility of Twitter Takes a Hit)
Symantec's spokesman called today's action "One of those strange anomalies that may have happened before to other firms but not to us."
Symantec joins a club that grows one unexpected flash move at a time.
