Four Rules for Crypto Investing
Control crypto risk through sizing, patience, diversification, and research
- Difficulty
- Easy
- Time to result
- ~days to results
- Steps
- 4
- Confidence
- 98%
Harvey's four rules turn speculative interest in crypto into a basic risk-control process. First, recognize that crypto is exceptionally volatile and avoid margin, which multiplies the damage from sharp price moves. Second, adopt a long-term perspective before investing so a market crash does not trigger bandwagon selling at the bottom. Third, diversify the entire portfolio rather than putting all available capital into crypto, and diversify within the crypto allocation instead of relying on a single token. Fourth, understand what each asset represents, how its protocol works, and why it could create future value. Together, the rules constrain exposure, discourage reactive trading, reduce concentration, and require research before capital is committed.
Origin
Campbell Harvey laid out the four numbered rules in response to a question about how an investor should put speculative money to work on Masters in Business.
Core principles
- 01Extreme volatility requires conservative position sizing.
- 02Leverage magnifies an already substantial risk.
- 03A long horizon reduces the temptation to sell after a crash.
- 04Diversification applies both across and within asset classes.
- 05Every token investment needs an understood economic rationale.
How to run it
- 1
Respect volatility
Estimate how much of the position could disappear during a severe crypto winter. Keep the allocation small enough to withstand that outcome and avoid margin.
Pro tip Size the position against a large drawdown rather than recent gains.
Watch out Leverage can double exposure to an asset class that is already exceptionally volatile.
- 2
Set a long horizon
Decide in advance whether the investment thesis can survive a multi-year cycle. Avoid buying during euphoria and selling after a collapse.
Pro tip Write down the conditions that would invalidate the thesis before purchasing.
Watch out A long horizon cannot rescue an asset with no durable value.
- 3
Diversify exposure
Keep crypto as one component of a broader portfolio and spread the crypto allocation across multiple researched assets. Avoid making one token responsible for the portfolio's outcome.
Pro tip Set maximum allocation limits for both crypto overall and individual tokens.
Watch out Owning many highly correlated or low-quality tokens may provide little genuine diversification.
- 4
Understand the asset
Investigate what the token represents, how the protocol functions, and where sustainable demand might originate. Invest only when you can explain the thesis independently.
Pro tip Describe the token's utility and risks without referring to its recent price performance.
Watch out Do not substitute a recommendation, social-media tip, or celebrity endorsement for due diligence.
In the wild
An investor allocates only a small portion of a diversified portfolio to several researched crypto assets, uses no margin, and adopts a multi-year horizon. When prices fall sharply, the investor can reassess the underlying theses rather than being forced to liquidate.
→ The portfolio absorbs the drawdown without a margin call or panic sale.
Harvey describes investors who bought bitcoin near twenty thousand dollars in 2017 and sold near five thousand dollars after the 2018 crash. The loss reflected bandwagon behavior and an inability to maintain a longer-term perspective.
→ The example demonstrates why entry discipline and a predefined horizon matter in volatile markets.
Common mistakes
Using margin
Leverage magnifies crypto's already extreme volatility and can force liquidation during an otherwise survivable drawdown.
Following the bandwagon
Buying after a surge and selling after a crash converts volatility into a permanent loss.
Treating familiarity as research
Knowing a token's name or hearing a recommendation does not establish what it represents or why it should create value.
Is it for you?
Best for
They are best for crypto-curious investors making a small, experimental allocation.
Not ideal for
They are not a substitute for professional advice, security planning, or detailed token valuation.
From the transcript
“you need to be going into this uh without margin fully knowing that we could have another situation where you lose crypto winters.”
“So so you need to have a longer term perspective. That's number two.”
“You need to do your homework and figure out what this token is really representing.”
From the episode
Campbell Harvey on the Future of Finance (Podcast)
Campbell Harvey