Drawdown, and why it is not the same as a loss

Drawdown is path-dependent, which means it depends on the sequence of prices and not only on the endpoints. Two investments can have identical starting and ending values and completely different drawdown histories. One may have risen steadily; the other may have doubled, halved, and doubled again. The final value is the same, and the experience of holding them is not remotely similar.

This is why a return figure alone cannot describe an asset's risk. An investment that returns fifty per cent over five years with a maximum drawdown of ten per cent is a different proposition from one that returns fifty per cent with a maximum drawdown of seventy per cent, even though the headline number is identical. The second requires a holder to sit through a period in which most of their capital has disappeared, and many holders do not. The drawdown is the measure that captures the risk of being forced to sell at the wrong moment.

Bitcoin's record illustrates the point sharply. The asset has produced very large long-horizon returns and has also produced declines of more than ninety per cent from a running peak. Both facts are true of the same series. A reader who takes only the return figure has taken the half of the record that is pleasant to read, and the drawdown record supplies the other half.

Maximum drawdown is the largest such decline over a chosen period. It is the standard summary of downside risk because it describes the worst experience an investor could have had by buying at the worst moment and selling at the worst moment. For Bitcoin, the maximum drawdown over the full record is the 2011 episode, when the price fell from roughly thirty-two dollars to two — a decline of more than ninety-three per cent. No later episode has come close, and that is the single most important fact about the asset's downside.

Recovery time is the interval from the peak to the point at which the price first exceeds that peak again. It is measured from the peak rather than the trough because the investor who bought at the top is underwater for the whole interval. The 2013 peak took 1,132 days to recover; the 2017 peak took 1,095; the 2021 peak took 846. Those are long periods to hold a losing position, and they are the reason drawdown analysis matters more than the headline return figure for anyone whose time horizon is uncertain.

The two measures are usually read together. A shallow drawdown that takes years to recover is a different risk from a deep one that recovers quickly, and a reader who looks at only one of them will misjudge the other. The recovery time page publishes both intervals for every episode, and the risk-adjusted returns page shows how the same downside appears when it is expressed as a ratio against return.