Does cash keep up with inflation over the long run?
The short answer
Barely, at best. From January 1947 through June 2026, something that cost $1 in 1947 came to cost $15.53, and a dollar kept in cash held onto about six cents of its buying power. $1 in Treasury bills grew to $20.79, just ahead of prices, while $1 in broad U.S. stocks grew to $5,864 for investors who stayed through every downturn.
How much buying power cash has lost since 1947
Since 1947, consumer prices have risen more than fifteen-fold. What $1 bought in 1947 costs $15.53 now.
Inflation has averaged about 3.5% a year over these eight decades. That sounds modest, but at that pace prices double roughly every 20 years. A retirement that lasts 25 or 30 years will watch the cost of living double at least once.
Cash feels safe because the number on the statement never falls. Inflation lowers what that number buys.
A dollar kept in cash since 1947 held onto about six cents of its buying power.
What has outpaced inflation
Growth of $1 from January 1947 through June 2026, with the annualized rate over the period:
- Consumer prices (CPI): $15.53, about 3.5% a year
- Treasury bills: $20.79, about 3.9% a year
- Broad U.S. stocks, dividends reinvested: $5,864, about 11.5% a year
What it took to earn the stock return
Treasury bills, the classic safe asset, finished barely ahead of the $15.53 needed just to break even with prices.
Broad U.S. stocks grew the same dollar into $5,864. That reward came only to investors who stayed through every downturn along the way, including some that cut the market roughly in half.
How this shapes a portfolio
For a long-term plan, inflation works as a slow leak. Money you'll need soon goes on the safe side. Money that has to outrun prices for decades goes in stocks.
About these numbers
The growth-of-$1 figures are hypothetical illustrations computed from monthly data, January 1947 through June 2026. U.S. stocks are the CRSP total U.S. market return and Treasury bills are the one-month T-bill return, both from the Ken French Data Library. Consumer prices are the CPI-U from the U.S. Bureau of Labor Statistics.
The figures assume reinvestment of all income and reflect no fees, taxes, or trading costs. An index can't be purchased directly, and past performance doesn't guarantee future results.
Takeaway
Since 1947 prices have risen more than fifteen-fold. Treasury bills barely kept up, and stocks turned $1 into $5,864 for investors who stayed through the downturns.
Related questions
How fast do prices double at 3.5% inflation?
Roughly every 20 years. At that pace, a retirement that lasts 25 or 30 years will watch the cost of living double at least once.
Have Treasury bills kept up with inflation?
Barely. From January 1947 through June 2026, $1 in one-month Treasury bills grew to $20.79, about 3.9% a year, against $15.53 needed to keep pace with prices.
Sources
U.S. stocks are the CRSP total U.S. market return (market return plus the risk-free rate) and Treasury bills are the one-month T-bill return, both from the Ken French Data Library, monthly data, January 1947 through June 2026.
Consumer prices are the Consumer Price Index for All Urban Consumers (CPI-U, not seasonally adjusted), U.S. Bureau of Labor Statistics. The October 2025 CPI reading was not published. That single month is interpolated for charting.
Disclosures
This material is for educational purposes only and is not investment, legal, or tax advice or a recommendation to buy or sell any security. Growth-of-$1 figures are hypothetical illustrations built from monthly data, January 1947 through June 2026, using the sources listed above. They assume all income is reinvested and reflect no fees, taxes, or trading costs. Annualized rates over the period: U.S. stocks 11.5%, Treasury bills 3.9%, inflation 3.5%. Indexes cannot be invested in directly. Past performance does not guarantee future results. Investing involves risk, including possible loss of principal. Cornerstone Wealth Partners is an SEC-registered investment adviser. Registration does not imply a certain level of skill or training.
This article is for educational purposes only and is not personalized investment, tax, or legal advice. Talk with a qualified professional about your situation.
