# How the plan projection works: 5,000 paths from market history

> How Anacleto projects a savings plan by recombining blocks of past monthly returns, what the percentiles mean, and why it is not a forecast.

Updated 2026-10-17 · https://anacleto-zb7h.onrender.com/guides/monte-carlo-projection

The [plan page](https://anacleto-zb7h.onrender.com/plan) answers "where could my monthly contribution take me?" without assuming a fixed return.

## The method

Anacleto builds **5,000 paths** by recombining **blocks of 24 consecutive months** of past returns, in random order:
US equities (S&P 500) converted to euro, US government bonds hedged to euro, and gold in euro, from 1997 onwards. Using blocks rather than single months keeps the way markets
move in streaks: crises and recoveries stay together. Each path applies your contributions, the weights your rules
produce, trading costs and the ongoing charges of your ETFs, and is expressed in **today's euros**, net of inflation.

## Reading the result

- the **median** is the middle path: half end above, half below;
- the **10th–90th range** contains eight paths out of ten;
- the **probability of your goal** is the share of paths that reach it.

## Limits

The paths can only rearrange the past: a future worse than anything in the history used is not in them. Taxes are
not included. It is a way to see the range of outcomes, not a forecast.