Using the hidden five-eights account, Leeson began to trade aggressively in futures and options on the Singapore International Monetary Exchange. His decisions routinely resulted in losses of substantial sums and he used money entrusted to the bank by subsidiaries for use in their own accounts. He falsified trading records in the bank's computer systems and used money intended for margin payments on other trading. As a result, he appeared to be making substantial profits. However, his luck ran out when the Kobe earthquake sent the Asian financial markets—and with them, Leeson's investments—into a tailspin. Leeson bet on a rapid recovery by the Nikkei, which failed to materialise.