Buy Term and Invest the Difference (BTID)

Buy term and invest the difference is the argument that permanent life insurance is a bad bundle: buy inexpensive Term Life Insurance for protection, invest the premium savings in market index funds, and you'll end up richer than the whole-life buyer. Popularized by A.L. Williams in the 1970s ("Buy term and invest the difference!") and carried forward by mainstream personal-finance media, it's the default advice most people encounter first.

The spreadsheet version can work. Market index returns have historically outrun whole life's steady growth, and for a disciplined investor who actually invests the difference, every month, for thirty years, through every crash, the math can favor BTID.

Real life keeps failing the assumptions. The behavioral one first: study after study shows the "difference" mostly gets spent, not invested — and investors who do invest earn far less than the indexes because they buy high, sell low, and pause contributions in exactly the years that matter. The insurance assumption fails next: term expires, and the roughly 98% of term policies that never pay a claim include many people who still wanted coverage at 65 but found it unaffordable or — after a diagnosis — unavailable. The Convertible Term option exists precisely because insurability isn't permanent.

The comparison also misprices what Whole Life Insurance actually is. It's not an equity substitute; it's a bond-like foundation with properties the brokerage account lacks: guaranteed growth, Creditor Protection (Life Insurance) in most states, tax-free access via policy loans, a permanent Death Benefit, and the collateral function that powers Infinite Banking. Whole life competes with the safe layer of a portfolio — cash, bonds, CDs — and against that layer it compares very well. Stocks-versus-whole-life was always the wrong fight.

The grown-up answer is usually both: term for the big temporary protection need, properly designed whole life sized to real cash flow as the foundation and banking system, equities on top for growth. "Term AND invest — through the difference" describes the I&E position better than either slogan.