Volumes of snp 500 vs bank nifty

Now this is totally out of curiosity
i was checking the volumes traded on bank nifty in investing.com
Now here it’s showing volumes are close to 3.3 million which comes to around 82527 contracts traded on 20th April 2018 ( 82527x40= 3301080 ) Completely matches the data with nse website and same with nifty also but in SnP500 mini the volumes are 1,577,913 on 19th April and 1,044,851 on 18th April
So my question is aren’t they suppose to be in multiples of the lot size i,e 50 or are they the number of contracts traded (in that case the volumes should be 78895650 ) please enlighten

What’s shown in volume is number of contracts not the quantity.
You can go to the link given by you from barchart.com and place the cursor on the volume it clearly states it is the number of contracts traded that particular day.


Thanks …Donno how i missed it