Loan-to-Invest Calculator
Finance kits
Compare borrowing a lump sum to invest at once against dollar-cost averaging — see the break-even return rate and the gap in annualized returns.
With 20-plus years before you need the money and the nerve to hold through crashes, you can tilt hard toward growth. But 'aggressive' isn't 'reckless' — this page shows exactly how deep the downside gets when you chase the highest return.
Two assets, one question: how much in each? Set their return and volatility, and let the simulation find your optimal split.
Capital & horizon
Asset A
Asset B
Optimize for
Picks the split with the best return per unit of risk (CAGR ÷ volatility). Usually an interior blend, since diversification lowers risk faster than it lowers return.
Ending wealth by allocation
Based on 168000 simulated paths. A simplified lognormal model — not a forecast. Real markets have fatter tails and shifting correlations; treat these as rough odds, not promises.
Under these assumptions, the best mix lands near 50% QQQ / 50% SOXX. After 25 years that blend's median outcome is about 46.1M, with a rough-patch (10th-percentile) value near 10.7M.
These figures use this scenario's example returns and volatility — swap in your own holdings' numbers in the calculator above.
This scenario pairs two high-growth, high-volatility equity sleeves (Nasdaq 100 and semiconductors) and targets the highest median, so the optimiser pushes toward whichever has the higher long-run return. The number to study is the P10 (rough-patch) cell: the median looks great, but the downside is deep. Whether you actually capture that median depends on whether you can hold through a -50% year.
Good fit: people around 30 with a 20-year-plus horizon, steady cash flow, who have already lived through one big crash without selling.
Watch out: semiconductors and tech are highly concentrated, and brutal when the sector turns. The historical returns here run hot — dial expected return down and look again. The closer you are to needing the money, the less of this you should hold.
This is a free side project I built in my spare time. If it saved you time or helped you think through a decision, buying me a coffee keeps the lights on!
How should you split capital between two assets? Set each one's CAGR and volatility, choose their correlation, and simulate thousands of paths to find the allocation that maximizes risk-adjusted return, median wealth, or downside protection.
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