Two former currency traders from Deutsche Bank AG and HSBC Holdings Plc were sentenced to jail terms of as long as 15 weeks for cheating the banks by making false trades.

Former HSBC senior dealer Ivan Chng was sentenced to 15 weeks in jail, Singapore High Court Justice See Kee Oon said on Wednesday. Ex-Deutsche Bank trader Toh Hway Khuan was given an eight-week sentence. Neither man was fined.

The two were convicted in January of using their banks’ accounts in 2009 to get preferential rates on the dollar. Singapore is toughening up on enforcement in the financial industry, with the regulator setting up a new unit to boost surveillance. The city saw its first front-running case and the largest market-rigging prosecution in its history last year.

Justice See said the men were motivated by self interest and gained a trading advantage. While the losses to the banks couldn’t be quantified with precision, the trades represented an opportunity cost to the banks, he said. The men made “substantial six-figure” gains through dishonest means and deliberate deception of the banks, according to See, who also said the trades were done within the market spread and that there was no discernible impact on the market.

The former traders were charged in 2015, with Chng, 48, facing 149 counts of buying and selling about $800 million and unlawfully making about S$230,000 ($162,000). Toh, 51, had 39 counts of buying and selling more than $250 million and unlawfully making about S$140,000.

Prosecutors had sought a three-month jail term for Toh and six months for Chng to deter those in the financial industry from making personal gains through deceitful means. Both men failed to disclose their beneficial ownership in the trades, and their offenses were difficult to detect, prosecutors had said.

Actual Losses

The duo’s lawyers had urged the court to impose a fine rather than a prison sentence. Toh’s lawyer Lee Teck Leng had said Deutsche Bank didn’t suffer actual losses and there was no market impact from his trades. The former trader has been jobless since being fired from the bank in 2010.

Chng had succumbed to the temptation of making money on the side, his lawyer Thong Chee Kun said. Chng, who exceeded HSBC’s annual target of $4 million in trading profits for 2008 and 2009, was fired from the bank and had to work as an Uber Technologies Inc. driver, his lawyer said.

Neither man plans to appeal the sentences, according to their lawyers.

The offenses happened around the time the Monetary Authority of Singapore was reviewing attempts by banks to rig currency benchmarks between 2007 and 2011. The regulator censured 20 banks in 2013 and ordered them to improve internal controls. Probes into the rigging of foreign-exchange markets and interest-rate benchmarks have led to lenders across the globe paying billions of dollars in fines and an overhaul of how such rates are set.

The criminal cases are Public Prosecutor v Toh Hway Khuan, CC6/2017 Singapore High Court, and Public Prosecutor v Ivan Chng, CC5/2017 Singapore High Court.