Should You Add Crypto to Your Investment Portfolio?
Few investing questions split smart people more than this one. The crypto-true-believer crowd insists it belongs at 25–50% of any modern portfolio. The traditionalist crowd insists it belongs at 0%. The honest answer for most investors sits somewhere in the middle, and depends entirely on your time horizon, your tolerance for extreme volatility, and your willingness to be wrong.
What "crypto" actually means in a portfolio context
For portfolio purposes, "crypto" almost always means Bitcoin (BTC) and Ethereum (ETH). They are by far the largest, most liquid, and most institutionally accepted. Smaller "altcoins" are a different beast — wildly speculative, often correlated with each other to the point of being one bet, and frequently subject to outright collapse.
A defensible portfolio crypto allocation is mostly BTC, optionally with some ETH, and very rarely anything else.
The volatility argument
Bitcoin's annualised volatility has historically run around 70–80%. The S&P 500 sits around 15–20%. That means BTC swings roughly four times as violently as the stock market. Drawdowns of 50% within a year are normal. Drawdowns of 70–80% have happened multiple times.
If a 50% drop in part of your portfolio would cause you to panic-sell, do not own crypto. The volatility is the price of admission, and there is no way to enjoy the upside without sitting through the downsides.
The correlation argument
Early bulls argued crypto was uncorrelated with stocks — a true diversifier. The data over the last several years tells a more nuanced story. Crypto has trended toward modest positive correlation with risk assets, especially in stress periods. In 2022, both stocks and crypto fell together, and crypto fell harder.
So crypto is not the magic diversifier some claim. But it is also not perfectly correlated with stocks either, and at small allocations it can still meaningfully shift portfolio behaviour.
What a small allocation historically did
If you had added 5–10% Bitcoin to a 60/40 portfolio over the last decade, the result was usually:
- Materially higher CAGR
- Materially higher volatility
- Materially deeper drawdowns
- Higher Sharpe ratio in some periods, lower in others
Whether that is a good trade depends on what you are optimising for. If pure return: yes. If smooth ride: no.
The "money you can afford to lose" principle
The most honest framework for sizing a crypto position is this: pick an amount such that, if it went to zero tomorrow, you would be annoyed but not financially harmed. For most investors that ends up being 2–10% of investable assets. Anyone telling you to put 50% in crypto is either selling something or has a survivor-bias view of the asset class.
Correlation, regulation, and the unknowable future
Bitcoin's history is short — about 15 years — and most of that history has been one of explosive growth. Future returns will not look like past returns, full stop. The asset class is also in the middle of an evolving regulatory environment that could meaningfully change institutional access either positively or negatively.
What this means: do not extrapolate Bitcoin's CAGR into the future the way you might extrapolate the S&P 500's long-run average. The S&P has 100 years of data. Bitcoin has 15.
Try the simulation
What-If Portfolio supports BTC-USD, ETH-USD, and most major cryptos. Build a 90/10 portfolio of VT and BTC-USD, then compare it to plain VT over 5 years. Look at the CAGR, the max drawdown, and the volatility. Then build a 50/50 and compare again. The numbers will make the trade-off concrete in a way no article can.