The headline comparison that broke portfolio theory
From 2014 to 2024, a $10,000 investment in Bitcoin turned into roughly $3.5 million. The same $10,000 in the S&P 500 became about $37,000. That 100x outperformance is why Bitcoin has broken into institutional portfolios despite the volatility that would otherwise disqualify it. But the headline CAGR is only half the story. The other half is risk, measured most simply as volatility, and the Sharpe ratio puts them on the same ruler.
This calculator lets you plug in your own CAGR and volatility assumptions for both assets and see not just final dollars, but the risk-adjusted return (Sharpe) for each. Plug in Bitcoin at 25% CAGR with 75% volatility and the S&P 500 at 10% CAGR with 16% volatility — then watch the Sharpe ratios come out much closer than you'd expect.
Why volatility is half the math
A 20% CAGR sounds great until you realize you had to sit through three 60% drawdowns to get it. For most investors, the ability to stick with an asset through a drawdown is more important than the headline return — because selling in a panic turns paper losses into real ones. Bitcoin's 75% annualized volatility means a 1-sigma move in a year is ±75%. The S&P 500's 16% volatility means a 1-sigma move is ±16%. Those are completely different experiences, and a calculator that ignores volatility is lying by omission.
The Sharpe ratio calibration
Sharpe = (expected return − risk-free rate) / volatility. Using a 4% risk-free rate (current T-bills), 10% return, 16% vol — the S&P 500 scores (10−4)/16 = 0.375. Bitcoin at 25% return and 75% vol scores (25−4)/75 = 0.28. By this measure, the S&P 500 is actually more efficient per unit of risk — even though Bitcoin has higher absolute returns. If you bump Bitcoin's CAGR to 40%, the Sharpe flips to 0.48 — better than stocks. The input assumption does all the work. Be honest with yourself about what you really expect going forward.
Allocation theory meets reality
Modern portfolio theory says the right allocation to Bitcoin is the one that maximizes your total-portfolio Sharpe ratio — which for most risk profiles is 1-5% of total wealth. Aggressive allocators go to 10-20%. Anything above 20% is concentration risk masquerading as diversification. Run the calculator and ask yourself: at what allocation does a 70% Bitcoin drawdown become tolerable? For most people the answer is 3-5% of net worth. Use our portfolio rebalance tool to set and maintain that target.
Tax asymmetry
S&P 500 index funds in a Roth IRA or 401(k) grow tax-free. Bitcoin in a taxable account grows with capital gains drag. A 10% S&P return in a tax-advantaged account can easily beat a 15% Bitcoin return in a taxable one once you net out the 23.8% long-term cap gains rate (federal) plus state tax. Run your numbers through our crypto tax calculator before deciding which bucket is actually more efficient.
What the data actually shows
Over rolling 4-year windows since 2014, Bitcoin has outperformed the S&P 500 in about 85% of windows. Over rolling 1-year windows, it's closer to 60%. And in bad years (2018, 2022), Bitcoin fell 75% while the S&P fell 5-25%. Returns are asymmetric, not normally distributed. That's why naive Sharpe calculations understate the tail risk of crypto — and why sizing matters more than picking.
Correlation is rising
Bitcoin was originally uncorrelated with stocks — a portfolio diversifier. Since 2020, correlation with the Nasdaq has run 0.4-0.7 in most windows. That means Bitcoin no longer provides the diversification benefit it once did. In a 2022-style downturn, both crashed together. If you hold both as diversifiers, you're less hedged than you think. Consider stablecoin yield or gold for true decorrelation.
Bottom line
Bitcoin has beaten the S&P 500 on absolute return. It has roughly matched — sometimes beaten, sometimes lost to — the S&P 500 on risk-adjusted return. Your personal experience depends almost entirely on whether you can hold through the drawdowns. Use this calculator to stress-test your assumptions, then size your position so the worst-case drawdown is one you can actually stomach without panic-selling.