Two federal employees retire with the same balance, the same allocation, and the same annual withdrawal. One retires into a bull market. The other retires into a crash. Their average returns over the next fifteen years can be nearly identical, yet one runs low while the other finishes ahead. The order of returns, not just the average, decides the outcome. This tool shows you that difference using the TSP funds' real published history: pick two start years and compare the same retirement, fifteen years forward, side by side.
This tool runs entirely in your browser. Nothing you enter is saved, transmitted, or seen by ThriftTrading. Returns are the C and G Funds' actual calendar-year results computed from TSP's own published share price history, 2005 through 2025. Fifteen-year windows, so start years run 2005 through 2011. Withdrawals are held level for clarity; real spending usually grows with inflation, which makes a bad early sequence worse.
While you are saving, a crash is an inconvenience. Your contributions keep buying shares at lower prices, and time repairs the damage. In retirement the machine runs in reverse. Every withdrawal taken during a downturn sells shares at depressed prices, and those shares are gone when the recovery arrives. That is why a loss in year one of retirement does far more damage than the same loss in year ten, even though both look identical in an average.
The comparison above makes the stakes concrete. A 2008 retiree holding stocks watched a large piece of the account disappear in the first year while withdrawals continued. A 2010 retiree with the same balance, mix, and spending started with three strong years instead, and the gap between the two accounts never closed. Same plan, same funds, different starting month on a calendar nobody controls.