Bill Bernstein Coward's Portfolio: Rolling Returns

When holding the Bill Bernstein Coward's Portfolio, how long should you stay invested to have high probability to achieve a positive return?

Over the selected period (~50 years), the longest duration with a negative return was 61 months (from February 2004 to February 2009).

This indicates that, within the same timeframe, any rolling period of 62 months or more has consistently resulted in a positive return.

Understanding this metric is crucial as it highlights the importance of a safe investment horizon. Knowing the minimum duration required to likely see positive returns helps investors set realistic expectations and reinforces the strategy of staying invested through market cycles. This approach can mitigate the emotional reactions to short-term market fluctuations and enhance the likelihood of achieving financial goals.

Previous vs subsequent Returns

Is there a correlation between past and future returns over all 10-year rolling periods?

The following chart illustrates the relationship between past returns (x-axis) and subsequent returns (y-axis).

Data points are aggregated to show occurrences, and you can zoom in by clicking or drawing over the desired area.

As of Oct 31, 2025, the annualized return of the previous 10 years has been 7.00%.

Rolling Returns

A rolling return is a measure of investment performance that calculates the return of an investment over a set period of time, with the starting date rolling forward. This approach can provide a more accurate representation of the investment's historical performance and helps investors to evaluate the investment's consistency over time.

Rolling Period Analysis

By selecting the 'Rolling Period', the chart and data will update. To study a different date range, change the simulation settings.