Mark Cuban Warns Retirees About the Cost of High-Interest Credit Card Debt

Mark Cuban has long warned that high-interest credit card debt can be more damaging to wealth than missing out on stock market gains. His approach is straightforward: eliminate high-interest debt first, build a cash cushion, and then invest in low-cost, diversified funds.
The average credit card interest rate on accounts carrying balances reached 22.15% in the second quarter of 2026, according to Federal Reserve data, compared with the S&P 500’s historical average annual return of roughly 10%. For retirees, Cuban argues that paying off expensive debt can effectively provide a better return than investing while carrying those balances.
Cuban has also recommended maintaining at least six months of income in cash before investing. For retirees, financial planners may recommend an even larger reserve to avoid selling investments during market downturns to cover unexpected expenses.
For long-term retirement investing, Cuban has repeatedly favored inexpensive, broad-market index funds, including low-cost S&P 500 funds, rather than complex strategies or individual stock picking.