Looking back to the 15th, 308.25ish was the hard resistance before a surprise gap up. The bears are currently trying to drive the price below that number and close a weighter candle under it. If the hourly closes below 308.25 about, we can likely expect some more selling.
What about the bulls? 310 is the magic number. Hourly closes 309.57 should pull 310 onto the table.