As you can see, the numbers are similar to those in 2011, with a slight 2.5% drop to reach $2,911 trillion. But I think that we can still call that a round €3 trillion, especially as I previously showed that there a number of major players that don't get reported. Specifically, we can certainly add a large number for CME (Chicago Mercantile Exchange). I downloaded their 2012 report here and found (on page 36) the following useful table showing that in 2012 they handled a notional value of $806 trillion - down quite a lot from the $1068 trillion in 2011, and way down on the $1227 trillion handled in those wonderful days back in 2008 (!)
Another big player that doesn't get fully reported is the DTCC. Their annual report for 2012 boasts about the fact that they handled $1.6 quadrillion in transactions. Specifically, they handled $743 billion of equities per day, $1,116 trillion in US Fixed Income Clearing, $110 trillion in Settlement and Asset Services Transactions, and $2.6 trillion in Wealth Management Services, as you can see from the figures on their web page. Of those, the $110 trillion makes it into the BIS report, and probably the Fixed Income Clearing numbers (although there are some differences).
Finally, there is the Options Clearing Company that handled 2 268 097 319 transactions in 2012, with a premium value of $744 328 498 181, although it is not clear what the actual value of those transactions would have been (OCC doesn't appear to publish those numbers).
So, I think that we can probably count on something close to the $5.5 quadrillion figure for US financial transactions that I had reported for 2011.
But for the UK, it is again depressing to see that the City of London has yet again managed to accidentally forget to provide the numbers to the BIS. Here's what I get by looking at the numbers in the BIS report which add up to £217 trillion.
Yet again, there is nothing for LCH.Clearnet Ltd - the company that reported £863 trillion in transactions in 2008 but has not revealed any figures for 2010, 2011 and 2012. And I notice that the figures from CREST have dropped by 63% to just £48 trillion. I think that my estimate of £1.76 quadrillion for UK financial transactions in 2011 is likely to have been maintained in 2012.