South Korea’s foreign exchange authorities have asked major brokerages to disperse dollar-buying orders throughout the trading day to ease pressure on the won.

According to industry sources on Tuesday, officials met nine securities firms on Friday to review dollar demand driven by individual investors, whose U.S. net stock purchases hit a record six-point-eight-billion U.S. dollars last month.

Because most firms buy dollars in bulk at 9 a.m. to settle overnight purchases made with integrated margin accounts, the government says demand spikes at the bell have been weakening the won.

Authorities suggested either switching to an average-rate settlement or immediately converting to avoid the morning surge.

Brokerages, however, said system changes cannot be made quickly due to technical and stability concerns.