A bullish divergence occurs when prices fall to a new low while an oscillator fails to reach a new low. This situation demonstrates that bears are losing power, and that bulls are ready to control the market again—often a bullish divergence marks the end of a downtrend
They're lots of Divergences, whether bullish or bearish in a scenario, sometimes you can determined by their strength. The strongest divergences are Class A divergences; exhibiting less strength are Class B divergences; and the weakest divergences are Class C. The best trading opportunities are indicated by Class A divergences, while Class B and C divergences represent choppy market action and should generally be ignored. You can find here for more info (investopedia.com/trading/trading-divergence-and-understanding-momentum/)