Band volume. Tongda letter didn't hear that the system comes with this indicator, and I didn't see the source code of this indicator after checking online. But I see such indicators.

Then make one.

The effect is as follows: I made a screenshot from the trend section of the online band volume and price analysis index. The network screenshot intercepted the Shanghai and Shenzhen 300 futures, and I intercepted the Shanghai and Shenzhen 300 index.