You can read more about it by following the link below:
Essentially OBV allows you to eliminate a lot of the noise from day to day movement and get a clear idea which direction it is headed in. Price and are highly correlated as you can see by looking at the chart.
On the OBV, I have added a horizontal black line where OBV has clearly pivoted recently. OBV isn't going to help much in determining price so much as price momentum. Prices below the horizontal line tend to be lower (but aren't always) than the prices below the line. This is relative. For instance, you shouldn't apply this months back. You use it to look at more recent price action not to compare today to several months ago.
You'll notice that OBV is below the horizontal line and has not moved dramatically lower. This helps explain the recent flat price.
The OBV should also help - in conjunction with other patterns and indicators - when to buy or sell . For instance, it may not be a great time to go long since the direction of price isn't clear. Should the continue to decline, then price will likely decline with it.
I agree. I created yesterday some long-term charts using volume indicators:
Weis Wave Volume
Volume Price Confirmation
You can find more here:
P.S. There are several versions of the OBV, I will test which one is the best.