Because it is a calculated Index, and does not actually trade by itself, there is no calculation done by any of the fundamental analysis sites.
For instance the calculation is - the dollars traded for every transaction (each price multiplied by number of shares traded individually) and then dividing by the total shares traded for the day.
But it does not actually trade....so no dollars are traded, and there are no transactions.......there might be some synthetic versions of the XTL which trade and can have a VWAP calculated - but then the VWAP would be for them, and actually not for the XTL.