In a day when Alibaba took the headlines, it was left to the Russell 2000 and Semiconductor Index to warn of potential change.

The Russell 2000 experienced a large bearish engulfing pattern, although within the boundaries of the declining channel. There was an undercut of the 200-day MA, which will need to be watched on Monday. Shorts could get aggressive with a stop above 1,164 (and/or declining channel line).
 

The semiconductor index also experienced a bearish engulfing pattern, which doubled as a 'bull trap'.  This is a decent short side opportunity with a stop above 660. Technicals are clinging to the bull side, so watch for a bullish reaction on Monday.
 

The S&P experienced huge volume trading on Friday, but there was little net change on Thursday's close. Given the volume, it's hard to look past a retest of 1,987, but it's going to take more than Friday's selling to hand market control over to bears.
 

The Nasdaq didn't finish with a bearish engulfing pattern, but did with bearish cloud cover.  Friday's action keep things inside the range, and bulls should wait for a break of 4,601 to trigger a new breakout.
 

For Monday, bears have a chance to generate some follow through. However, stops need to be kept  tight.  Even a strong upside gap on Monday might be enough to nix the short side play.