According to this study by the CFA Institute, three quarters of hedge fund managers think the outlook for computer-driven strategies is troubled. (HT Fintag). The surveyâs findings do reflect part of the long-held view that quant strategies have had their day. If pre-crunch those strategies were plagued by diminishing returns and a crowded marketplace, post-crunch theyâve been plagued by big losses, investor withdrawals and a few spectacular collapses. By and large, itâs inadequate models that are blamed. But, as the CFA studyâs authors write: The conclusion of this discussion is that what appears to be model breakdown may, in reality, be nothing more than the inevitable fat-tailed behavior of model errors. The models, in other words, are perfectly accurate, but inadequately applied. Here, of course, itâs probably worth making a distinction: broken and inaccurate modelling has characterised a lot of the travails in the markets over recent months, but not always at the hedge funds. Rating agencies in particular, were using some pretty outdated assumptions. In rating products such as leveraged super seniors, CDOs squared, or market value structures like CPPIs and CPDOs, rating agencies were using spread modelling techniques several years out of date; none of which had tails fat enough. Given how critical market liquidity was to all those structures, it becomes meaningless to talk of what happened as a â25-sigma eventâ. Anyway, as the studies authors conclude, quant funds are most certainly not dead. The trick for them going forward will be to move beyond linear models based around Gaussian (or normal) distributions and instead trying to think of models which can move from ânormalâ market environments to âfat tailâ environments dynamically and adjust investment strategies accordingly: Eliminating the tails from noise would be an exceedingly difficult exercise. One would need a model that can predict the shift from a normal regime to a more risky regime in which noise can be fat tailed. Whether the necessary data are available is problematic. http://ftalphaville.ft.com/blog/2008/05/20/13185/quant-quanto-quando/ Challenges in Quantitative Equity Management http://www.cfapubs.org/doi/pdf/10.2470/rf.v2008.n2?cookieSet=1
so......... they will be moving a little in the direction of martingaling possibly? I wonder how many once in a hundred years events per month this new breed of hedgies will be able to fend off............