Ian Ow and his father Ow Weng Fye want compensation of S$896,871 ($715,607) from Clariden Leu and their former banker Aaron Chwee, after Ow was allowed to trade futures contracts, which resulted in losses.

The lawsuit has been filed at the Singapore High Court, and a closed hearing is scheduled for next month, the report said.

“The trades were carried out through the instigation of Chwee without any consultation with WF Ow,” the Ows said in their lawsuit cited by Bloomberg. “Clariden did not take reasonable care as any prudent bank would have.”

Clariden Leu declined to comment. In an emailed statement the bank said: "It would not be appropriate for Clariden Leu to comment on an ongoing legal proceeding."

Ian Ow, who was considered a minor under Singapore law when he traded in Singapore MSCI futures contracts in 2007, was convinced by Chwee that Clariden had the systems in place to make trades which would be profitable and risk free, according to court papers. The age of majority in Singapore for purposes including voting is 21. It was lowered to 18 for entering most contracts in 2009.

Both father and son were “sophisticated and knowledgeable investors,” Clariden Leu said in its defense. Ian Ow’s trades are also binding as he was no longer considered a minor under Swiss laws at the time of the trades in question, the bank said as reported by the newswire.

Ian Ow was financially astute and had been trading in foreign currencies through a leveraged margin account when he and his father opened an account with Clariden in 2006, Chwee said. His father had instructed Chwee to take orders from his son, said Chwee, insisting that he had briefed the son on the risks.

Parent company Credit Suisse is absorbing Clariden Leu this year, resulting in 550 job cuts, Switzerland’s second-biggest bank said in November.