©iStock/plusphoto There's panic on Wall Street and around the world recently, and it's not bad economic news or a terrible earnings report that's at fault. Instead, it's a highly leveraged yen "carry trade" that has led to billions of dollars in selling and liquidations starting in the crypto market on Sunday night.Here's how the yen carry trade works. Borrow yen at a low interest rate. Convert yen to another currency, often U.S. dollars. Buy assets that yield an interest rate higher than the Yen rate in (1). Ex. U.S. treasuries. According to the Motley Fool, if yields and exchange rates don't change, this is a brilliant trade because it is a simple arbitrage that prints money month after month. They go on to say: But something has changed. The interest rate on Yen debt is rising; the prior range was 0% to 0.1%, and the Bank of Japan announced a rate increase to 0.25% on Friday, bucking a decade-plus trend of essential zero rates.