NEW YORK ( TheStreet) -- Cisco ( CSCO) triggered a circuit breaker at 10:41 a.m. Thursday and the Dow started a 100 point slide 19 minutes later. Think investors are a bit jittery? There may be no connection between a wayward Cisco trade and the market swoon, but the two events underscore the how uncertain investors are about the market in the aftermath of the so-called flash crash of May 6.
Cisco joined Citigroup ( C), The Washington Post ( WPO), Genzyme ( GENZ) and Anadarko ( APC) on the list of stocks that have triggered the new single stock circuit breaker rules established on June 16 to prevent another wild, largely computer-generated sell off. Cisco shares were halted briefly Thursday morning when an order, apparently for 100 shares, was mispriced at $26. The price exceeded the 10% range barrier established as part of the new single stock circuit breaker rules. The NYSE Amex issued this statement on the Cisco trade: 11:46 AM 07/29/2010 Market Operations Update CEE Review Initiated for CSCO NYSE Amex has reviewed trades executed at 10:41:33 a.m. ET at and between $23.67 and $26.00 in Cisco Systems Inc. (CSCO) and determined that all trades will stand. This decision is not subject to appeal. A "CEE review" is "Clearly erroneous execution," according to a NYSE Amex representative. "It's a notice that trades are being reviewed to determine whether they are erroneous." Though probably unintentional, the new circuit breaker rules now serve as an occasional reminder of all the potential flaws in an already volatile market. The uncertainty and fear of a crash has caused many investors to buy what they call crash insurance. This is typically done by asking a broker to put in an order for an S&P 500 ETF like SPY ( SPY) well below the current trading price. This gives them protection if SPY falls dramatically. This rush-to-crash insurance has created big jumps in options trading around SPY. The volume jumped 116% Wednesday, the biggest move in four years, according to one observer. "Cisco halted for tripping a circuit breaker" may not be the headline that takes everyone's breath away, but it reminds people of how unsteady the market can be. --Written by Scott Moritz in New York.