FIRE retirement tools that use forward-looking data

Tools built for early retirement planning

Why FIRE planners need forward-looking assumptions

FIRE planning has a uniquely long time horizon. If you retire at 35, your portfolio needs to last 50-60 years. Over that timescale, the difference between using historical returns (which bake in a 40-year bond bull market) and forward-looking estimates (which account for current yields and valuations) is enormous.

J.P. Morgan's 2026 Long-Term Capital Market Assumptions project lower returns for US equities and bonds than the historical average. Planning on the historical 8-10% equity return when the forward estimate is lower means your Monte Carlo success probability is overstated. You could be making FIRE decisions based on return expectations that are unlikely to materialize.

Sequence risk and fat tails

The biggest risk in early retirement is not average returns. It is the order of returns. A market crash in your first few years of withdrawal can permanently impair your portfolio, even if average returns recover later.

Portfolio Lab's Monte Carlo simulator uses Cornish-Fisher adjustment, which models the actual shape of return distributions including fat tails and negative skew. Standard simulators assume returns are normally distributed, which understates the probability of exactly the scenarios that destroy FIRE plans.

The Bitcoin question

Should a FIRE portfolio include Bitcoin? The quantitative answer depends on your assumptions. Using J.P. Morgan's geometric return estimate of 15% with 42.5% volatility, mean-variance optimization suggests a 5-15% allocation improves risk-adjusted returns for most portfolio profiles.

The key insight: at a 10% allocation, a 50% Bitcoin crash costs you 5% of total portfolio value. At a 5% allocation, it costs 2.5%. These are survivable drawdowns within a diversified portfolio. The Bitcoin Allocation Calculator shows exactly how different sizing affects your overall risk and return.

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