NEW YORK (TheStreet) -- In what could be be a major blow to ultra-long and utra-short ETFs, the Financial Industry Regulatory Authority announced Tuesday that it would be raising margin requirements for leveraged ETFs on Dec. 1. In Regulatory Notice 09-53, FINRA notes that it will be implementing increased customer margin requirements for leveraged ETFs and uncovered options overlying leveraged ETFs. Leveraged ETFs like the Direxion Daily Financial Bull 3X(FAS Quote) and Direxion Daily Financial Bear(FAZ Quote) have become increasingly popular with investors over the last year. These funds use derivatives like futures and swaps to achieve ultra-long or ultra-short...