I've highlighted 2 examples.
1. Classic Divergence - As price exceeded the lower in the price fall at the end of August, you can see the OVB make a higher low after it crossed below then back above the lower BB. A nice long trade followed.
2. The first day after Labor Day saw gold have a huge day up. As price hit the upper cyan BB (Std Dev 1.0), the OBV also showed all the buying pressure. That signaled the end of the buying as OBV dropped the next day. You can see that it preceeded the crossover by a day. GC