hi, just have a question for the tax experts out there.... i only traded futures for tax year 2008, but i decided on april 15, 2008 to elect MTM treatment for securities only (not futures) just in case i decide to trade stocks going forward. i understand that to complete the MTM process, i have to file form 3115 (change in accounting method) by the filing deadline for tax year 2008 (oct 15, 2009). what happens if i don't file form 3115? will it cause problems? or will it just invalidate the request for MTM treatment. thanks, mgarc