Foreign-exchange dealers say they have the solution to the high-frequency trades eroding banks’ profits across financial markets. A currency-dealing platform known as ParFX, established in 2011 by firms from Deutsche Bank AG to Citigroup Inc., was approached last month by banks asking if its technology could be applied to other asset classes, Chief Executive Officer Dan Marcus said. The system works by pausing trades at random to prevent dealers with high-powered computers from jumping in front of investors and gaining an advantage. “These banks do need to trade foreign exchange because it’s their business and ... (full story)