“Goldman Sachs Group Inc (GS.N) lost tens of millions of dollars after a computer glitch led to a flood of erroneous options trades last week, a source close to the matter said on Monday.

“Last Tuesday, an upgrade of Goldman’s internal system affected options on stocks and some exchange-traded funds with symbols beginning with the letters H through L, leading to trades vastly out of line with market prices.

“Roughly 80 percent of the erroneous option-market contracts traded on NYSE Euronext’s two option platforms NYSE Arca Options and NYSE Amex options were cancelled, according to a second source close to the situation.

“The two platforms have collectively handled about 23 percent of equity and index options trading in August, according to data from OCC, formerly known as the Options Clearing Corp, which clears all U.S.-listed options.”

***

Read full Reuters article here