這是QQQ 半小時圖

After it flashes sell signal (you can see that "Sell" from the trading system) at 475 yesterday, has been on a downtrend since.

Today, huge volume in first 2 bars to take it down, and has been up and down controlled by day traders with small volume

We need a larger volume to push this back above BB mid-band to even start think about rebound.

Similar chart can be seen on 1hr and 4 hrs