So I've got a rate of change indicator with the source being OBV. The periods I've set for this is 4. Im having abit of confusion as to how the currency rate of change figure is being derived. Does it look at the last four periods including the current candle stick . E.g 1-2-3-4-5 ( If it was the 5th candlestick it looks at 2-3-4-5) or ( Does it look at 1-2-3-4, therefore not including the current candlestick). I ask this because went i look back at a candle stick 10 minutes back it  changes the rate of change number. 

Sorry for the long winded question. And thanks in advance. :)

Regards Navraj.

The rate of change plots the net change in OBV between the value four candles ago and the current value.

If 1 is the current candle it calculates the change from 5 to 1.

I still dont understand something. Lets say im looking at a 2 minute chart, same settings as i mentioned. and the candle in question is the 11.32 candlestick. Lets say the Rate of change is 500k. Why does this keep changing during the 11:50 Candle stick? By changing i mean the RoC number has changed on the 11:32 candle stick since its close.

With Gold, the consolidated tape data is delayed by 15 minutes. The latest 15 minutes on the chart only includes trades from the BATS exchange.  Once it is 15 minutes old, the BATS data is replaced by data from the consolidated tape. I think this is why the prior values are changing.

oh I see, so if i upgrade it wouldnt change? as the data is in real time.

Exactly.