IMHO this seems to be a lame effort, all the organizations involved in this competition aren't significant players in data mining or alg trading field.
Its more of top coder rather than Netflix
I don't like the binary view of things. In the real algo trading world, no one is forcing you to take a long or short position-- flat is a viable option.
Thanks Tansey, your comment helped me to fix a trading algo I've been working on for weeks.
will next year's contest be predicting predictions? my prediction for future stock prediction algorithms is approximately this: http://www.ofb.net/~egnor/iocaine.html
I'm told the 2012 comp will involve predicting the predictions of predictions.