An astonishing number, as Tom Petruno points out here, because most of that cash is making next to nothing, and everyone who holds it is losing money because of inflation:
[I]nvestors who want absolute safety for their money are sticking with cash. Lots of cash.
Since 2008, millions of individuals and corporate investors have sharply boosted what they hold in cash accounts at banks. The total in basic savings and money market deposit accounts has reached a record $5.58 trillion, up from $5.09 trillion a year ago and $4.03 trillion three years ago, according to Federal Reserve data.
There's an additional $2.7 trillion sitting in money market mutual funds.
Most of the combined $8.3 trillion in those cash accounts is earning close to zero interest. That's a massive chunk of capital producing almost no return for its owners. To put it in perspective, the sum in cash accounts is 52% of the value of the entire U.S. stock market as measured by the Wilshire 5,000 index.