I have $N$ strategies, across a variety of assets and time frames (from intra-day to month holding times). Each strategy is sort-of-kind-of market-neutral and mostly carrying idiosyncratic risk. Since we all know it's not really true, I do evaluate the market-factor risk for each strategy position (delta, vega, correga, whatever applicable) to get an understanding of my gap/systemic risk. On the other hand, strategies do go boom because of idiosyncratic reasons - some stock goes bust like Enron in one of my single name strategies or maybe Obama decides to sell tons of S&P skew to improve the morale. This is non-controllable risk that I simply need to diversify away.
So, this brings multiple questions:
- assuming that I got the market-risk modeling under control, how do I assign an idiosyncratic risk value to a strategy? I was thinking of some sort of Poisson process, but can't even think of how to properly combine multiple distributions in that case.
- is there a clean way to construct a portfolio allocation model that on one hand will neutralize market risk but on the other hand would keep idiosyncratic risk diverse enough for me to sleep at night?
- how do i include the dynamic nature of each strategy in the allocation process? For example, some strategies are expiration-date specific, some fire fairly infrequently etc. Do I allocate hard dollars? Do I look at the new signals and allocate given the current risk in the portfolio?