Investment Return Scenarios: Understanding Expected, Optimistic, and Pessimistic Projections

What the Three Scenarios Mean

Investment calculators typically show three scenarios to account for market uncertainty. The expected scenario uses your entered rate of return (typically 6-8% for a balanced portfolio, reflecting long-term stock market averages). The optimistic scenario uses 1.5 times your expected rate. The pessimistic scenario uses half your expected rate.

For retirement planning, it is wise to use the pessimistic or expected scenario — not the optimistic one. Planning for the optimistic scenario risks coming up short. The pessimistic scenario helps ensure you save enough even if markets underperform.

Historical Context

The S&P 500 has averaged approximately 10% annual returns before inflation (7% after inflation) over the past century. However, this average masks enormous variability: some years are up 30%, others down 40%. A 7% expected return with a 3.5% pessimistic and 10.5% optimistic range accounts for this variability while remaining historically grounded.