I've been examining in more detail the data set provided by the Bank for International Settlements that provides information on the level of transactions for the period 2012-2019. Today, I'm giving you the breakdown by country for the whole period.
The bottom line is that over the 8 year period, there were $96,790,943,000,000,000 of financial transactions ($97 quadrillion).
I suspect that some of the numbers may be double counted. For example, BIS gives the data for CLS Group on a separate line marked "Memo". It may be that some of the trading is actually also included in the US or the UK figures. They also mark the numbers for the "Euro area" with "Memo", suggesting that those numbers may be double counted with other Eurozone countries. But I'm doing my best, and the BIS doesn't seem to be clear about how the tables are compiled.
If you want to try and analyse the BIS statistical data set yourself, you can find it here. But, I warn you, it's quite hard work! To find out how I compiled the dataset, I you can find my Google Sheet analysis here. I've even made it so that you post comments on the sheet if you see anything that is unclear.
It's really rather a shame that nobody was listening when, 10 years ago, I proposed that we could replace essentially all existing taxes by a very modest financial transaction tax. At a rate of 0.1% it could have generated getting on for $100 trillion in revenue. We could have fixed climate change, eliminated poverty and done all sorts of very desirable things.
Better late than never I suppose....