Maximum drawdown measures the largest drop from a peak to a trough in the value of an investment before a new peak arrives. If your portfolio once fell from $15,000 to $9,750, your maximum drawdown was 35%. That single figure tells you what the worst stretch actually cost, something that average returns and volatility quietly hide.
In this guide you will learn what maximum drawdown is, why it matters more than most investors admit, how to calculate it step by step, how real crashes from 1987 to 2022 compare, and the mistakes that make people misread it. It is written for investors who already know the basics and want a sharper risk lens.
Maximum drawdown is defined as the largest peak to trough decline over the history of a variable. Source: Wikipedia, captured 21 October 2026.
What Is Maximum Drawdown?
A drawdown is the decline from a previous peak in the value of an investment, a portfolio, or a trading strategy. It is measured from the highest value reached so far down to the lowest value reached before a new high. Maximum drawdown, often shortened to MDD or Max DD, is the single largest of those declines over the period you are studying.
The formula is simple. Take the peak value, subtract the trough value, and divide the result by the peak value. If an account peaks at $15,000 and later bottoms at $9,750, the calculation is ($15,000 minus $9,750) divided by $15,000, which equals 35%. Any drop that happens after a new peak is measured from that new, higher peak.
Three related terms often get mixed up, so it helps to separate them before going further.
Drawdown terms at a glance
Maximum drawdown is also the foundation of several risk-adjusted performance measures. The Calmar, Sterling and Burke ratios all replace the standard deviation used in the Sharpe ratio with some function of the drawdown. If you want the volatility side of the story first, read our guide to the Sharpe ratio and then come back here for the downside view.
Why Maximum Drawdown Matters
Volatility tells you how much a price wobbles on an average day. Maximum drawdown tells you how much money you would have watched disappear at the worst moment, which is the number that decides whether you stay invested or panic. Two portfolios can share the same average return and the same volatility, yet one can have a far deeper and longer drawdown. Most investors prefer the shallower one, even if a spreadsheet says they are equal.
The deeper reason is arithmetic. Losses and gains are not symmetrical, because a loss shrinks the base you are climbing back from. A 50% fall needs a 100% gain just to break even. The table below shows how quickly the required recovery grows.
The recovery math every investor should memorise
78% fall in the Nasdaq Composite between March 2000 and October 2002, erasing every gain made during the dot-com bubble.
Notice how the final row is not a matter of patience. A 78% loss demands a gain of more than 350%, which is why investors who held a concentrated tech portfolio waited years, and in many cases decades, to see their old peak again. Maximum drawdown is the metric that makes this cost visible before you take the risk, not after.
There is also a behavioural reason. Investors rarely abandon a plan because of average returns. They abandon it during the deepest drawdown, usually near the bottom. Knowing your portfolio's historical worst case in advance is one of the few tools that lets you decide, calmly, whether you can actually live through it. A solid emergency fund helps here too, because it stops a drawdown from forcing you to sell at the worst moment.
The Nasdaq Composite rose about 600% between 1995 and March 2000, then fell 78% by October 2002. Source: Wikipedia, captured 21 October 2026.
How to Calculate and Use Maximum Drawdown
You do not need special software. A spreadsheet with a column of portfolio values is enough. The process has six steps, and the same logic powers every backtesting tool you will meet.
Step 1: Collect the value history
Gather the value of the portfolio, fund or strategy at regular intervals. Daily closing values are best because month-end data can hide deep dips that recover inside the month. Make sure the series includes dividends or uses a total return figure, otherwise you will overstate the drawdown.
Step 2: Track the running peak
In a second column, record the highest value seen so far at every row. In a spreadsheet this is a running maximum: each cell takes the larger of the previous peak and the current value. The running peak only ever moves up or stays flat.
Step 3: Compute the drawdown at each point
In a third column, calculate (running peak minus current value) divided by running peak. This gives the drawdown on every date. It is zero whenever the portfolio sits at a new high and positive whenever it sits below its peak.
Step 4: Take the maximum
The largest number in the drawdown column is your maximum drawdown. In the $15,000 example, the value fell to $9,750, so the maximum of the column is 35%. Note the dates of the peak and the trough as well, because you need them for the next step.
Step 5: Measure duration and recovery
Count the time from the peak to the date the portfolio first closes above that peak again. This is the drawdown duration. A 20% drawdown that heals in four months is a very different experience from a 20% drawdown that takes four years, and only the duration figure shows the difference.
Step 6: Size your position against your tolerance
Now turn the number into a decision. Suppose a stock fund has fallen 50% at its worst and you know you would lose sleep beyond a 25% portfolio loss. Holding roughly half your money in that fund and the rest in cash or high-quality bonds keeps the expected worst case near your limit. This is a rough rule because assets rarely move independently in a crisis, so leave a margin of safety.
To compare strategies on a return-per-pain basis, divide the annualised return by the maximum drawdown. This is the Calmar ratio. A strategy that earns 12% a year with a 30% maximum drawdown scores 0.40, while one that earns 9% with a 15% drawdown scores 0.60, so the second compensates you better for the pain involved.
$15,000 to $9,750 is a 35% maximum drawdown, and it takes a 53.8% gain to get back to the peak.
Real Examples: Five Crashes Compared
History gives the best calibration for what a drawdown can look like. The table below summarises five well-known episodes using widely reported index figures.
Major equity drawdowns
The 2020 episode shows why you should always read the depth and the duration together. The decline was among the fastest on record, with the crash beginning on 20 February 2020 and the market bottoming within weeks, yet the recovery was also quick. The dot-com bust is the opposite case: a smaller number of headline weeks, but a drawdown measured in years.
20.47% one-day fall in the S&P 500 on 19 October 1987, and the Dow Jones Industrial Average fell 22.6% the same day.
Broad index funds have survived each of these drawdowns and eventually reached new highs, which is one reason diversified index funds remain the default core holding for long-term investors. Individual stocks and concentrated bets have no such guarantee, and some of the 2000 era leaders never returned to their peak.
The harbour wall mark from the introduction applies here. The 1987 crash, the 2000 bust and the 2008 crisis are the high-water marks of fear in the modern market. A plan that has never been tested against them is a plan built on the average depth.
Common Maximum Drawdown Mistakes
Mistake 1: Treating the past maximum as a ceiling
A historical maximum drawdown is a floor under what has already happened, not a limit on what can happen. Every new crisis sets a new record for some asset. If a fund has a 20% maximum drawdown over five calm years, expect a deeper figure in the future, perhaps by a wide margin.
Mistake 2: Using too short a history
A backtest covering only a bull market can show a maximum drawdown of 8% and look nearly risk free. Always include at least one full cycle with a bear market, and ideally the 2000 to 2002 and 2007 to 2009 periods. If the data does not exist, say so and assume the real figure is worse.
Mistake 3: Ignoring drawdown duration
Two funds with a 30% maximum drawdown are not equal if one recovers in nine months and the other in six years. Duration measures the time your capital is stuck, which matters most if you need to withdraw money soon. Always check both.
Mistake 4: Using month-end or yearly data
Low-frequency data smooths out the lows. A portfolio can fall 25% inside a month and recover by month end, leaving the monthly series looking calm. Use daily data for any serious calculation and compare the result with the monthly figure.
Mistake 5: Chasing a zero drawdown
A strategy with a tiny maximum drawdown often has a tiny return, or hidden risk that has not shown up yet, such as selling insurance against rare events. Lower risk is useful only if the return per unit of drawdown, such as the Calmar ratio, stays attractive. Smooth lines on a backtest deserve extra suspicion.
The 2020 stock market crash began on 20 February 2020 and ended on 7 April 2020. Source: Wikipedia, captured 21 October 2026.
Frequently Asked Questions
What is a good maximum drawdown for a portfolio?
There is no universal number, because the right level depends on your time horizon and temperament. A common rule of thumb is to choose a portfolio whose historical worst case you could sit through without selling. Many diversified stock portfolios have seen drawdowns of 50% or more, while balanced portfolios of stocks and bonds have usually fallen less. Pick the level at which you stay calm, then size your holdings to fit.
How is maximum drawdown different from standard deviation?
Standard deviation measures how widely returns scatter around the average in both directions, so it treats a big gain as risk too. Maximum drawdown looks only at the loss from a peak, which is what investors actually feel. Use both: volatility for the everyday ride and drawdown for the worst case.
How long does it take to recover from a maximum drawdown?
It depends on the depth and on the market. The 2020 decline recovered within months, the 2007 to 2009 decline took several years to reach a new index high, and the dot-com decline took the Nasdaq Composite well over a decade. The deeper the fall, the more the recovery arithmetic works against you, as the table earlier showed.
Can maximum drawdown exceed 100%?
Not for an unleveraged long investment, since the value cannot fall below zero. With leverage, short positions or margin, losses can exceed the capital you put in, which is why traders pay close attention to drawdown limits before they use borrowed money.
Does dollar cost averaging reduce maximum drawdown?
Investing a fixed amount on a schedule does not change the index's drawdown, but it changes your experience of it. Your later purchases happen at lower prices, so your recovery can be faster than for a lump sum made at the peak. Our guide to dollar cost averaging explains the trade offs.
Key Takeaways
- Maximum drawdown is the largest peak to trough fall in value, expressed as a percentage of the peak.
- Recovery math is brutal: a 50% loss needs a 100% gain, and a 78% loss needs about 355%.
- Always read depth and duration together, since a long drawdown ties up your capital.
- Use daily data and at least one full bear market in any backtest, or the figure will flatter the strategy.
- Treat the past maximum as a floor, not a ceiling, and keep a margin of safety in your plan.
- Compare strategies with the Calmar ratio, annualised return divided by maximum drawdown, alongside the Sharpe ratio.
What to Watch Next
Drawdown is a live number, so track it rather than calculating it once. These checkpoints keep your risk picture current.
- Is your portfolio's current drawdown from its last peak now deeper than half of your stated tolerance?
- Has your maximum drawdown figure been refreshed since the last major market decline?
- Does the share of your portfolio in a single sector or stock exceed the loss you could accept if it fell 50%?
- Is the Calmar ratio of your main strategy holding above 0.5 over a rolling three year window?
This article is educational and is not personal financial advice. Past drawdowns do not predict future ones, so consider speaking with a licensed adviser before you change your investments.