The Russell 2000 could be up or down 1.2% at 8:30 tomorrow morning in premarket and neither would surprise me.
Reason I mention them is they're probably of most interest right now. If this index doesn't bounce like...soon, there's not much resistance underneath and the easiest path would be for it to roll over and likely take everything with them, a lot like how the Nasdaq took everything with them last fall, only it took a lot longer (months) to transpire this time.
Frankly surprised it's held up for as long as it has too. In March it went down over 9% as fast as it went up that much and hasn't done anything since.