Chinese credit tightening created a massive overseas sell off overnight and we'e seeing the spillover today although as of midday the markets have shrugged off almost all of the selling pressure and many issues including QQQ and IWM are in the green.
Going forward for the next couple months there's a curious disparity in potential volatility between SPY and QQQ and while I'm still trying to figure out why the bottom line is that the risk profile of SPY looks much more attractive than QQQ.