Considered here is on-line portfolio management aimed at maximizing the long-run growth of financial wealth. The portfolio is repeatedly rebalanced in response to observed returns on diverse assets. Suppose statistical information and related methods are not available - or deemed too diffcult....

We introduce an adaptive importance sampling method for the loss distribution of credit portfolios based on the Robbins-Monro stochastic approximation procedure. After presenting the subtle construction of the algorithm, we apply our adaptive scheme for calculating the risk figures of a typical...