After yesterday's sharp slump, the SPY return to a highly volatile market. SPY testing area above 308.1 - 310 and it has become intraday rebound strong resistance. The supporting area is 304.4-303.5. Pre-market stocks rose broadly, energy, airline, hotels, Banks, and yesterday's biggest faller varieties plate before rebounding, the biggest tech bellwether yesterday still keep above key support, days, or focus on Banks and technology bellwether. Today is Friday, the market will more likely repair yesterday drop.