Cryptocurrency basics
What a coin actually is, why prices swing 70% in a year, and how much of a portfolio, if any, belongs there.
Bitcoin and Ethereum have produced the two best-performing decades-long holding periods available to a retail investor. They have also produced drawdowns that no ordinary portfolio can absorb, twice, and both statements are true at the same time.
The question is not whether crypto is a good technology. It is whether you can hold an asset that falls 80% without selling — and the honest answer for most people is that they only find out afterwards.
What you are buying
| Concept | What it actually means |
|---|---|
| Blockchain | A ledger replicated across thousands of computers, where changing history requires controlling most of the network |
| Private key | The only proof of ownership. Lose the file, lose the coins — there is no support line and no reversal |
| Proof of work | Bitcoin's consensus mechanism: miners spend electricity to earn the right to add the next block |
| Proof of stake | Ethereum's mechanism since 2022: validators lock coins instead of burning power |
| Stablecoin | A token pegged to a currency, backed by reserves you have to take on trust |
| Smart contract | Code that executes on a blockchain; useful, and the source of most large crypto losses |
Nothing on that list generates cash flow. A share of stock entitles you to a share of future profits. A bond pays interest. A rental property pays rent. A coin pays nothing, which means its price depends entirely on what the next buyer will pay — and that is the definition of a speculative asset, not a moral judgment about it.
The drawdown problem
Drawdowns are the reason crypto behaves differently from every other asset in a portfolio, and not because of the depth alone. It is the recovery arithmetic.
Lose 50% and you need 100% to get back to even. Lose 80% and you need 400%. Lose 90% and you need 900%. This is not a subtle point about volatility; it is the reason a position that falls 84% requires a 525% gain before it has done anything for you.
A 94% drawdown needs a 1,567% recovery. Both assets did recover, which is exactly why the next one feels safe and is not.
Illustrative. Drawdown magnitudes are approximations of widely reported peak-to-trough moves; recovery figures are the exact arithmetic implied by each drawdown.
Now put that next to a stock market crash. The S&P 500 fell about 57% in 2007 to 2009, which requires a 133% recovery. That felt like the end of the financial system and took roughly five and a half years to recover in nominal terms. A 94% drawdown is not that experience with worse numbers. It is a different category of experience.
Position size decides everything
The most important number in crypto is not the entry price. It is the percentage of your portfolio it occupies, and the reason is mechanical.
At 5% of the portfolio, a 60% crypto drawdown costs you 3% overall — recoverable inside a year of normal market returns. At 25%, the same drawdown costs you 15%, which is several years of contributions. At 50%, a crypto winter is a personal financial crisis.
The asset does the same thing in all four bars. Only the size of the position changed, and the size of the position was your decision.
Illustrative. Assumes the remainder of the portfolio is unchanged and no rebalancing during the drawdown.
There is a second, quieter effect. Crypto is the asset class most likely to outgrow its allocation during a bull market, which means a 5% position becomes 20% without you buying anything. Rebalance on a schedule, and rebalance by selling into strength — which is emotionally the hardest trade in the whole portfolio and mathematically the one that protects you.
Where the money is lost
Price declines are the visible risk. Most permanent capital loss in crypto comes from somewhere else.
| Failure mode | What happens |
|---|---|
| Exchange failure | A custodian holds your coins, becomes insolvent, and account holders become unsecured creditors. This has happened at scale. |
| Lost keys | A hardware wallet without a backup is a single point of failure with no recovery path. Estates have lost fortunes to this. |
| Borrowed money | Liquidations convert a temporary drawdown into a permanent loss, often within hours |
| Yield products | Double-digit returns on stablecoins are lending in disguise, and the disguise fails in exactly the conditions that make it attractive |
| Fraud | Tokens with no product, promoters paid to post, and networks where dissent is labelled as disloyalty |
Notice that only one of those five is about price. The others are about custody, borrowed money and trust — and each of them is fully within your control.
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