Hello everyone,

I'm attempting to replicate the values I see on yahoofinance.com for Volume Rate of Change of the SPY ETF.  The equation is simple enough (V(0)-V(n))/V(n).  I'm trying to store the daily volume into an array and use the first and last element to compute my vROC. 

I know the list isn't built to be sequential, I really just needed to capture some of the data to compare to yahoo. I notice the volume I'm returning from my code isn't the same as the volume displayed for the same days on yahoo.  Do you know why this is?  Also, is there a more sophisticated way to store the volume data? My current setup will not store the data in correct order sequentially.

Thank you for you help!