This paper presents the results of a post—sample simulation of a
speculative strategy using a portfolio of foreign currency forward contracts.
The main new features of the speculative strategy are (a) the use of Kalman
filters to update the forecasting equation, (b) the allowance for transactions,
costs and margin requirements and (c) the endogenous determination of the
leveraging of the portfolio. While the forecasting model tended to overestimate
profit and underestimate risk, the strategy was still profitable over a
three year period and it was possible to reject the hypothesis that the sum of
profits was zero. Furthermore, the currency portfolio was found to have an
extremely low market risk. Combinations of the speculative currency portfolio
with traditional portfolios of U.S. equities resulted in considerable
improvements in risk—adjusted returns on capital.