Construct and compound each resampled path
For N observations and block length L, available blocks start at positions zero through N − L and do not wrap around the sample end. Select block starts uniformly with a seeded generator, concatenate their returns, and stop after H observations. A path return is [Π(1 + rₜ/100) − 1] × 100%. The tool supports up to 365 horizon observations and 2,000 simulations. Inputs cannot fall below −100%; a −100% simple return makes that compounded path lose all starting capital.
See what one block choice preserves
Take returns of 10%, −10%, and 0%, with block length two and a two-observation horizon. Available blocks are [10%, −10%] and [−10%, 0%]. Selecting the first compounds to 1.10 × 0.90 − 1 = −1%; selecting the second compounds to −10%. These are outcomes from the entered sequence, not newly estimated market events. A fixed seed makes repeated runs with identical inputs reproducible, including the number of times each available block is selected.
Percentiles describe the simulation design
Sort the simulated horizon returns and select empirical percentiles using nearest ranks. Changing block length changes how much original dependence survives inside segments, while the joins introduce artificial boundaries. A longer simulation count reduces resampling noise but does not repair missing crises, changing market conditions, or a biased input history. The distribution cannot create fundamentally new shocks absent from its source returns. Record the sample window, block length, horizon, seed, and simulation count whenever comparing or sharing results.