A small volume during an uptrend is divergence; volumes can occur in over-the-counter transactions and are simply not visible.

(Simple, visual, and so that you can apply it immediately — even if you're trading for the first day!)
1. 'Language of candles': what Japanese candles hide
Don't look at the color, but at:
- The length of the shadow (if the upper shadow is long = sellers are pushing the price up).
- Body of the candle (large green candle on volume = strong interest from buyers).