To hold 3 short strangles on GOOG, SPY and AAPL with a net credit of $4,600, Reg-T required margin is 24k while for Portfolio Margin its 35k. Hope some IB representatives can shed some light on this, it really doesn't make any sense that PM have higher requirements than Reg-t, in the worst case scenario it should have the same requirements as reg-t. You don't go through the hassle of applying for a pm upgrade and wait for approval just to to get less buying power than before 