It gives you a reference point for a tight stop.  I personally like to see a break below the 21 EMA, especially when it's at a key level, trap the sellers, and buy it on the 1st full candle above the 21.  If you buy the initial breakout, you're just asking to get trapped. They usually retest and do a final shakeout.  If that holds true, the next move higher in the Chinese names should be buyable (as long as we don't drop too far from here)

The biggest red candle in a given range is typically at bottoms and the biggest green candle is typically at tops.  The next candle doesn't have to be bigger, just needs to close in a way that traps all the volume from the previous candle...they have to cover and it's off to the races.

The biggest recent green volume candle on BABA was 24 Feb. They will be trapped on a close below 73.85. We're at 74.50 now.