As these dark pool implementations are not standardized.... Is the volume accurate reflecting all trades or just the non-dark pool trades?
does it matter? the volume of transactions is in the blockchain
is it important to know which transfer was exchange for currency and which was for goods/services?
in the museum of finland's central bank is a counter that shows volume cleared transactions in the finish electronic payment system. it does not have sub counters, just volume since last reset.
i see a similar approach should be just fine. velocity of bitcoins for past 24 hrs. no need to aggregate data from all known exchanges and attach the $/eur equivalent. what is it good for? ( i know what is it good for to know the volume of trades, but dark pools do not harm imo, same way as listing sum of all transactions does not represent exchanged value)