We have another new leader as TheStreet.com's Beat the Street contest enters its final day."Mardan59" used an all-short portfolio made up mostly of "credit-crisis" plays such as mortgage insurers and banks to take over the top spot. The portfolio, which totaled $302,696.90 after Thursday trading, consists of MBIA ( MBI), PMI Group ( PMI), MGIC ( MGIC), Washington Mutual ( WM), MF Global ( MF) and UAL ( UAUA). The contestants are playing for a $5,000 prize. Check back tomorrow evening to see who won.