Cash feels risk-free because its price never moves — but sitting in the wrong place, it can quietly lose value every single year. Here's the real math behind keeping cash safe, liquid, and not slowly eaten by inflation.
Cash and cash equivalents are the most liquid, lowest-risk layer of investing — physical cash, checking and savings accounts, money market funds, and short-term Treasury bills (maturing in a year or less). Unlike stocks or bonds, their nominal value essentially never drops: $1,000 in a savings account is still $1,000 tomorrow. But that stability comes at a cost — cash typically earns the lowest return of any major asset class, and if it earns less than inflation, it's quietly losing real value even while the number on the statement stays the same or grows a little.
A useful analogy: think of cash like keeping food in the fridge instead of the freezer. It's instantly accessible whenever you need it — no waiting, no risk of a bad thaw — but leave it there too long and it slowly spoils anyway. Cash doesn't "spoil" in the sense that the dollar amount ever falls, but its buying power quietly does, one percent of inflation at a time.
2022 is the clearest recent illustration of cash's real enemy. U.S. inflation peaked at 9.1% that June — while the average bank savings account was still paying almost nothing.
A typical savings account lost roughly 9 percentage points of real purchasing power that year alone, despite the balance never falling. Treasury bills and money market funds — which track short-term interest rates much more closely — climbed from near 0% in early 2022 to nearly 4% by year-end, still short of inflation but a very different outcome from a standard savings account.
Same $10,000, same 10 years, same 3% average inflation — the only difference is where the cash sits.
The checking-account balance never dropped below $10,000 — yet it can only actually buy what $7,441 buys today, a real loss of $2,559. Meanwhile the money-market-style account not only nominally grew to $14,381, its real purchasing power still came out ahead too, at $10,701. The balance on the screen isn't the whole story — what it can actually buy is.
Plug in your own numbers to see whether your cash is actually keeping pace with inflation — or quietly losing ground.
Model: nominal balance compounds at your interest rate; real purchasing power discounts that nominal balance by inflation over the same period. If your interest rate is below the inflation rate, the balance still grows on paper — but its real purchasing power falls.
Answer all five, then hit "Check My Answers" to see how you did. Get one wrong? No problem — the explanation will show you exactly why.
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Cash is the foundation — see how the other building blocks fit alongside it.