(So) What If You Miss the Market’s N Best Days?

An investor revisited a 1999 paper rejected by the Financial Analysts Journal for claiming a widely-cited argument against market timing is fundamentally flawed. The rejected paper argued that the common refrain—"you only have to miss the N best days to ruin long-term returns"—is logically incoherent because the same math produces an equally absurd counter-argument: missing the worst N days would justify market timing. The investor contends the argument persists today despite being "very dumb" and "obviously silly." The core problem: the exercise assumes an investor perfectly times the market to exit before the best days and re-enter after—a presciently incompetent strategy that would indeed be disastrous. But the same logic applied symmetrically (missing worst days instead) would argue for timing the market, revealing the framework as useless for either position. The investor's 1999 analysis, tested out-of-sample over 25 years, held up well, showing results align with what normal distribution assumptions would predict. The investor argues the real case against market timing is straightforward: most investors lack the skill to execute it successfully, and random deviations from a diversified portfolio are harmful. Rather than rely on the flawed "missing best days" framing, advocates should make this honest argument instead. The investor calls on practitioners still promoting the discredited logic to stop and respect their audience by using sound reasoning.