The banks sought to reduce their losses by trying to renege on transactions by contacting customers after the SNB decision, asking to discuss the rates they’d traded on, Bloomberg said. Some currency trading firms and major banks lost out when the SNB scrapped its three-year-old cap on the franc against the euro (EURCHF=EBS) without warning on Jan. 15. Barclays lost “tens of millions” of dollars and retail broker Alpari UK filed for insolvency.