NEW YORK/CHICAGO Aug 20 (Reuters) - A flood of erroneous trades hit U.S. equity options markets on Tuesday as they opened for business when Goldman Sachs Group sent orders accidentally because of a technical error, the latest trading problem to hit the options market this year.
Major options exchanges including platforms run by CBOE Holdings, Nasdaq OMX Group Inc and NYSE Euronext said they were reviewing the trades, sent in roughly the first quarter hour of trading and affecting options on shares with listing symbols beginning with the letters H through L.
Exchanges have the option to adjust prices or nullify, or "bust," the trades if they are determined to have been made in error. NYSE Euronext's NYSE Amex Options market said it anticipates most of the trades will be canceled.
Goldman Sachs said in a statement the firm does not face material loss or risk from the issue. The firm declined to comment further.
A person familiar with the problem, who declined to be identified, said the cause was a computer glitch in which indications of interest in equity options were sent as actual orders to the exchanges. Some of the orders were filled, while others were not.
Options market participants said the activity struck promptly as the market opened.
Many of the orders on some of the options for those stocks were 1,000-contract blocks traded for $1 per contract, WhatsTrading.com options strategist Frederic Ruffy said.
Stocks whose options saw some of the order flow included Johnson and Johnson, JPMorgan Chase and Co and Kellogg Co., Ruffy said.
Options on some exchange-traded funds, such as the iShares S&P Small Cap Fund, were also affected, he said.
Potential losses could range in the millions of dollars, the source said, but it was unclear just how many transactions were involved and what any final cost would be.
"There is no real obvious way to tell how much this cost traders," said Ophir Gottlieb, managing director of options analytics firm Livevol based in San Francisco. "But the ones that are hurt the most are likely the market makers who provide liquidity and are the counter parties."
It is another in a series of problems affecting exchanges. In April, a half-day outage at the Chicago Board Options Exchange exposed software problems that came about as it prepared to extend trading hours for futures contracts on the CBOE Volatility Index.
CME Group Executive Chairman Terry Duffy said in an interview on CNBC that busting trades is difficult because of different rules at different exchanges. The futures exchange operator was not affected by Tuesday's incident.
Nasdaq and CBOE "have to coordinate with the NYSE and the other institutions to make sure they all do the same thing because if trades stand at one institution and not at another it can be a big fallout for the participants and who gets those trades," he said.
A year ago, a software mishap at Knight Capital Group led to millions of unintended orders flooding into the market over a 45-minute period.