How do I stress test my portfolio?

Enter your holdings and weights, then replay them through real crisis windows (2008, 2020, 2022) to see the drawdown and recovery time, and optionally apply hypothetical shocks like an equity drop or rate spike. You can do it here free, no account needed.

How much would a typical portfolio have lost in 2008?

Roughly speaking, all-stock portfolios halved, while balanced stock/bond mixes fell far less because quality bonds cushioned the drop. The exact number depends entirely on your holdings — run the replay to get your specific figure.

Can a stress test predict the next crash?

No — it estimates how your current mix would behave in scenarios like past crises or specified shocks. The next crisis will differ, but a portfolio that survives several very different historical failure modes is far more likely to survive whatever comes.

Would Your Portfolio Have Survived 2008? How to Stress Test It

6 min read · Updated 2026-07-08

Every portfolio looks fine in a bull market. The only question that separates a durable allocation from a fragile one is: what happens when things break? Most investors find out the expensive way — live, mid-crash, right when they're most tempted to sell.

A stress test answers the question in advance. It takes your exact holdings and weights and replays them through real historical crises — or hits them with hypothetical shocks — so you know your worst case before it happens. Here's how to run one and what to do with the results.

Stress test your portfolio →

The two kinds of stress test

Stress testing comes in two complementary flavors:

•Historical replay — apply your current allocation to an actual crisis window (2008, 2020, 2022) and measure what it would have lost and how long recovery took. Grounded in real market behavior, including how correlations actually moved.
•Hypothetical shocks — apply a synthetic scenario (say, stocks −40%, or interest rates up 2 points) and estimate the hit based on how your holdings respond to those moves. Useful for scenarios history hasn't served up yet.

The three crises worth replaying — they break portfolios differently

The recent past conveniently includes three very different failure modes, which is exactly why all three are worth running:

•2008–09 (credit crisis) — deep and slow: broad equities roughly halved over many months, and recovery took years. Quality bonds cushioned the blow. This is the test of depth and patience.
•2020 (COVID crash) — fast and violent: a ~30%+ equity drop in weeks, then an almost equally fast recovery. This is the test of panic — whoever sold in March locked in the loss.
•2022 (inflation/rate shock) — the diversification failure: stocks and bonds fell together as rates rose sharply, so the classic ballast didn't work. This is the test of hidden rate sensitivity.

Broad US stock drawdowns in the three crises (approximate)

2008–09 credit crisis

−55%

2020 COVID crash

−34%

2022 rate shock

−25%

Approximate peak-to-trough for broad US equities — and in 2022, bonds fell double digits too. Replay your exact holdings in the tool.

How to read the results

Three outputs matter more than the rest. First, the total drawdown — is it within the worst case you consciously signed up for (your guardrails)? Second, the recovery time — a loss you carry for four years is a very different experience from one that heals in six months, especially if you're withdrawing. Third, the breakdown by holding — which positions did the damage, and which actually cushioned it? That last one often surprises people: assets they thought were diversifiers turn out to fall right alongside everything else.

Also check the coverage of the test: holdings without data in a crisis window (a fund launched in 2015 can't be replayed through 2008) mean the replay understates the true risk.

What to do if you fail your own stress test

If the replayed loss is deeper than you could genuinely tolerate — financially or emotionally — the time to fix it is now, in calm markets, not mid-crash. The usual levers: shift the stock/bond split toward your real risk level, replace overlapping holdings that all fell together with genuine diversifiers, and rebuild the cash buffer so a drawdown never forces a sale.

Then re-run the test on the adjusted mix and confirm the worst case is now one you can live with. That loop — test, adjust, re-test — is the whole discipline.

Make it a habit, not a one-off

A stress test reflects your current holdings, and portfolios drift — winners grow into oversized positions, and yesterday's balanced mix quietly becomes an equity bet. Re-run the test after meaningful changes or once a year. It takes minutes, and it's the cheapest insurance in investing: knowing your worst case while it's still hypothetical.

Try it yourself

Stress TestReplay 2008, 2020, and 2022 against your exact holdings.Open tool →Backtest PortfolioSee the full history — growth, drawdowns, and recovery times.Open tool →Risk Profile QuestionnaireSet the guardrails your stress-test results should stay inside.Open tool →

FAQ

How do I stress test my portfolio?: Enter your holdings and weights, then replay them through real crisis windows (2008, 2020, 2022) to see the drawdown and recovery time, and optionally apply hypothetical shocks like an equity drop or rate spike. You can do it here free, no account needed.
How much would a typical portfolio have lost in 2008?: Roughly speaking, all-stock portfolios halved, while balanced stock/bond mixes fell far less because quality bonds cushioned the drop. The exact number depends entirely on your holdings — run the replay to get your specific figure.
Can a stress test predict the next crash?: No — it estimates how your current mix would behave in scenarios like past crises or specified shocks. The next crisis will differ, but a portfolio that survives several very different historical failure modes is far more likely to survive whatever comes.

Key terms in this guide

Plain-English definitions in the Learning Hub.

Stress test →Equity shock →Interest-rate shock →Maximum drawdown →

Stop guessing — run the numbers on your own portfolio, free.