Our interest in doubling comes from the fact that it is potentially harmful to the system.
An important attribute of doubling strategies is that the inevitable and devastating loss is
preceded by a period of high returns with low volatility. Conditional on the bad event not
having happened (yet), the doubler’s investment performance appears to indicate
significant investment skill. The doubler may then become too big to fail, both from the
perspective of the investment firm and from the market regulators, so that the inevitable
failure can have catastrophic effects, both for the firm and for the market. Should
Leeson’s activities have been discovered and stopped one month earlier, i.e. by the end of
January 1995, the total loss would have been about one quarter of the eventual loss. This
could probably have been absorbed by Barings, saving the bank as an independent entity
(SR.ES36, p.B-i). Kane and DeTrask (1999, p.216) suggest that the Barings management
may even have known about Leeson’s exposures and allowed him to expand his bets as
their only chance to avert disaster.