The figure of $27 trillion refers to “Assets under custody or administration (AUA)”, which isn’t exclusively cash. It’s likely also much stocks (and as the Dow Jones from 2002 to 2008 almost doubled, and since collapse again recovered, the AUA would follow). The annual growth of AUA at BNY Mellon hasn’t accelerated compared to before the crisis (looking back prior to the merger of Mellon with the bank of New York in late 2006, to their combined AUA), see 2007 report page 4 (chart shows growth from something under $10 in 2002 to $23 trillion in 2007). The year of crisis 2008 saw a decrease to $20.2 trillion. 2009 (22.3 trillion) still no full recovery to the 2007 figure. 2010 growth to 25 trillion, 2012 lists 26.2 trillion. That is slower compared to the (hypothetically combined) growth before 2007. So I think Ticktin’s mention of $27 trillion should be seen as referring to the increased amount of AUA since the early 2000s. And as I mentioned the stock market increased about the same rate, so it is probably not mostly cash wish is “deposited” (I doubt it counts as deposits, since on the balance sheet there is given a separate deposit figure).

Now then, Ticktin might be better understood as referring to the growth of the stock market, which grows increasingly faster, it has been doing so since 1982. In turn the reason for that might be the devaluation of the dollar.

‘One serious mistake. We most certainly did not support the presence of British troops in Northern Ireland in 1972 (the year of Bloody Sunday). We did decide in a wholly different situation in 1969 not to call for the withdrawal of British troops (against the opposition of myself and others). By switching the date to 1972 you seriously misrepresent us.’