Everbright Securities suffered an unspecified problem with a computerized trading system and sent 7 billion incorrect purchase orders for shares.

Chinese stock prices have swung wildly after a brief buying frenzy blamed on a brokerage’s computer error.

Friday’s trading volume soared to 54 percent above the previous day’s level. That caused the main market index to spike up 6.5 percent before falling to end the day down 0.6 percent.

A brokerage, Everbright Securities, said it suffered an unspecified problem with a computerized trading system.

A government news agency, the China News Service (CNS), said Everbright sent 7 billion incorrect purchase orders for shares.

Share prices of 70 companies including market heavyweights PetroChina Ltd. and major state—owned banks surged by the 10 percent daily limit before falling back, according to CNS.

Everbright asked to have its trades canceled, CNS said. But a statement on the exchange website said any transactions that were completed would be cleared normally.

Phone calls to the Shanghai exchange’s press office were not answered. The exchange and securities regulators were investigating the incident, CNS reported.

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