Nasdaq, S&P 500 futures dip ahead of Fed rate decision

US stock futures fell as investors awaited the Fed decision and rising oil prices from Iran tensions. Retail sentiment turned 'bearish' on the Nasdaq but stayed 'bullish' on the S&P 500. POET dropped on Marvell order cancellations. Investors watched SLS for leukemia data and IBRX for buyout rumours.