the Japanese Nikkei 225 stock index, 10-year Japanese government bonds, and euro-yen deposits. Because they were traded simultaneously on the Osaka Securities Exchange (OSE) and the Singapore International Monetary Exchange (SLMEX), Leeson's job eventually became one of taking advantage of arbitrage opportunities between the two markets. But Leeson was not just arbitraging, and between July 1992 and February 1995 (about two and a half years). he incurred losses of over ฿1 billion. How was this possible?