WTMWHITE MOUNTAINS INSURANCE GROUP LTD— $500 a month, backtested
A dollar-cost-averaging backtest: a fixed amount (default $500 a month) invested into this stock on a fixed schedule, over real split- and dividend-adjusted (total-return) prices with dividends reinvested and no fees or taxes, compared against the same schedule into the S&P 500 (SPY) and a day-1 lump sum. Invested principal, end value and the money-weighted annualized return (XIRR) are engine-computed from historical prices, with no LLM. The Plan tab runs entirely in your browser on a return assumption you choose. The backtest is a historical statistic, not a prediction: past performance does not predict future results.
| Ticker | Valor final | Ganancia % | anualizado (XIRR) |
|---|---|---|---|
| Tu canasta (WTM) | $109,584 | +82.6% | +11.6% |
| Mismo plan en SPY | $136,330 | +127.2% | +15.7% |
| Suma única el día 1 (mismo total, misma canasta) | $154,649 | — | — |
Backtest 2016-08-01 → 2026-07-31 · 120 de 120 compras programadas ejecutadas
Un backtest de promediado de costes (DCA) sobre precios reales ajustados por splits y dividendos (rentabilidad total): a cuánto habría crecido invertir una cantidad fija en un calendario fijo, con dividendos reinvertidos y sin comisiones, impuestos ni límites de acciones fraccionarias, frente al mismo plan en SPY. Un dato histórico divulgado, NO una predicción, una garantía ni asesoramiento de inversión. La rentabilidad pasada no predice resultados futuros.
Promedio de largo plazo del S&P 500: un punto de partida neutral, no un pronóstico para WTM.
IMPORTANTE: Las proyecciones que genera esta calculadora son de naturaleza hipotética, calculadas únicamente a partir del supuesto de retorno que ingresaste. No reflejan resultados reales de inversión y no son garantía de resultados futuros. Excluyen impuestos, comisiones e inflación. Esto es aritmética sobre tus datos, no un pronóstico de Tickwind ni asesoría de inversión.
Cómo se calcula esto
- Se realiza una aportación de tu monto al inicio de cada mes (más la aportación inicial opcional en el mes 0).
- El saldo capitaliza mensualmente a (1+r)^(1/12) − 1, donde r es el retorno anual que definiste arriba.
- La banda de varianza, cuando está activada, vuelve a ejecutar la misma aritmética en r ± el ancho que elijas: no es un intervalo de confianza estadístico.
How the backtest works
- A fixed amount on a fixed schedule. Each monthly or weekly contribution is split across the basket at fixed weights and buys at that day’s adjusted close (fractional shares, no fees or taxes). There is no rebalancing: the basket drifts with performance, exactly like a real fixed-split auto-invest plan.
- Total return, not price-only. Prices are split- AND dividend-adjusted, so every curve already includes reinvested dividends.
- Buys execute on the first common trading day at or after each scheduled date across every basket ticker and SPY; a slot with no trading day of its own is skipped and disclosed - money is never silently doubled up.
- annualized (XIRR) is the money-weighted annual return that makes the dated contributions grow to the end value - the honest rate for a stream of contributions, where a simple CAGR would be wrong. It is omitted (—) on windows under a year rather than annualized misleadingly.
- The SPY row applies the identical schedule to the S&P 500 ETF; the lump-sum row shows the same total invested in the same basket on day 1 - the classic DCA-versus-lump-sum comparison, disclosed instead of implied.
- A historical backtest, not a forecast. A stat that cannot be computed honestly shows "—", never a fabricated 0. Past performance does not predict future results.
The backtest on this page is a disclosed historical statistic over real prices; the plan is hypothetical arithmetic on your inputs. Neither is a prediction, a price target, or investment advice. Past performance does not predict future results.