Silver futures suddenly dropped Thursday evening before quickly bouncing back in another so-called “flash crash” that renewed fears that computer-driven trading has gone too far.

Around 7:05 p.m., ET, the contract for September delivery plunged 11 percent lower from $16.14 per troy ounce to $14.34, according to FactSet. Silver traded near $15.89 per troy ounce Friday morning.

Traders could not name a fundamental reason for the drop, but considered it another case of computer-driven trading that disrupted markets during a period when few were actively trading. Like most other flash crashes in recent months, the drop in silver occurred outside of New York business hours and in the early hours of Asian market operations.

CME Group, which runs the NYMEX exchange on which silver futures are traded, did not immediately respond to a CNBC request for comment.

Silver futures 2-day performance

Source: FactSet

The drop in silver is the latest in a series of flash crashes in the last 12 months.

On June 21, bitcoin rival ethereum crashed in New York afternoon trade from near $317 to 10 cents on a major U.S.-based digital currency exchange called GDAX.

On the evening of May 4, U.S. West Texas Intermediate crude futures fell more than 3 percent from $45.36 to a near six-month low of $43.76 a barrel in about fifteen minutes.

In early October, pound sterling lost a tenth of its value in a sudden decline that sent the currency to a 31-year low.

The flash crashes have been relegated to derivative markets — trading of products with prices derived from other assets — after stock exchanges put in limiting mechanisms to prevent a repeat of a May 2010 crash. That was when the Dow Jones industrial average plunged nearly 1,000 points before recovering minutes later.

The latest action in silver raises the fears once again that computer trading has gone too far and doesn’t yet have the proper controls.

This will “probably continue to happen on a sporadic basis, especially now with the speed of electronic trading,” said Jim Wyckoff, senior analyst at Kitco Metals. “Derivatives, options, futures, all that’s probably continuing to create some unexpected volatility like that.”

“You can’t do much about them,” he said. “It just happens.”

— CNBC’s John Melloy and Tom DiChristopher contributed to this report.

Source: Investment Cnbc
Silver plunges in yet another mysterious market 'flash crash'