What Is a Bear Market? Definition, Every S&P 500 Bear Since 1993, and How to Manage the Risk

A bear market is not one thing. The 2020 crash erased 34% of the S&P 500 in 33 days and fully recovered in under five months. The dot-com bust erased 49% over two and a half years and took nearly five years just to get back to even. Both are "bear markets" by the same 20% definition - which is exactly why the definition alone tells you very little about what you're actually in for.

A bear market is officially defined as a decline of 20% or more in a broad market index from its most recent closing high. The number is arbitrary in the sense that nothing special happens at exactly -20% - but it's the threshold Wall Street, financial media, and most index providers have settled on to separate a bear market from an ordinary correction (a 10-20% pullback that happens in most years and is considered routine).

What the definition doesn't tell you is how deep the decline will go beyond -20%, how long it will take, or how long it will take to get back to where you started. Those three numbers vary more than almost anything else in investing.

Five Real Bear Markets, Five Very Different Shapes

Using SPY's full trading history back to its 1993 launch, here is every S&P 500 bear market on record - computed directly from daily closing prices, not estimated:

A few things jump out. First, depth and duration don't move together - the shortest bear market to reach bottom (2020, 33 days) was also one of the deepest (-34.1%), while the longest grind to a bottom (2000-02, 31 months) got there gradually. Second, recovery time is almost always longer than the fall itself, sometimes dramatically so: the 2007-09 crash took 17 months to bottom but another four full years to reclaim its old high. Third, the two most recent bear markets (2018, 2020) both recovered in under five months - not because bear markets got "easier," but because both were triggered by conditions (a rate-hike scare, a pandemic shock) that reversed quickly once policy responded, unlike the structural credit problems underneath 2007-09.

Across these five episodes, the average peak-to-trough decline was about -37% and the average decline took about 12 months to reach bottom - but recovery back to the old high averaged roughly 26 months, nearly double the fall itself.

These five bears only cover SPY's history since 1993. Going back further, the two deepest bear markets in US history happened before that window: the 1929 crash took the Dow down roughly 89% and didn't recover for 25 years, and the 1973-74 stagflation bear took the S&P 500 down about 48% with a real, inflation-adjusted recovery that stretched into the early 1990s. The full walk through those and the other major US crashes is in Every Major Stock Market Crash Since 1929.

The Four Types of Bear Markets

Not every 20% decline has the same underlying cause, and the cause is a better guide to how long it will last than the size of the drop:

1. Cyclical — tied to the normal business cycle, often triggered by a central bank raising rates to cool an overheating economy. Tends to be sharper but shorter. The 2018 selloff fits this pattern: the Fed was hiking into a slowing global economy, sentiment cracked hard in December, and the moment the Fed signaled a pause, the market recovered within months.
2. Event-driven — a sudden external shock unrelated to underlying economic fundamentals: a pandemic, a war, an oil embargo, a bank run. Can be very fast and very deep, but recovers quickly if the shock itself resolves or is offset by policy, as in 2020.
3. Structural — a systemic problem inside the financial system itself: overleveraged banks, a credit bubble, counterparty risk that cascades. The 2007-09 crisis is the template. These tend to be the deepest and slowest to recover because the damage has to work its way through balance sheets, not just sentiment.
4. Secular — the slow deflation of a broad speculative bubble across an entire asset class or sector, rather than one triggering event. The 2000-02 dot-com bust fits this: no single crash day, just a multi-year unwind as internet-stock valuations came back to earth.

Bear Market Rallies Are the Trap

Every bear market on the table above included sharp, multi-week rallies of 15-20%+ that ultimately failed and rolled over to new lows before the real bottom. The 2007-09 crisis alone had several 20%+ rebounds that reversed. These bounces are common enough that they have their own name and their own warning signs - see Bull Traps and Bear Traps: Avoid False Breakouts and Dead Cat Bounce Explained for how to tell a real reversal from one that's about to fail again.

Which Sectors Hold Up Best

Bear markets don't fall evenly. Sectors with more stable demand regardless of the economy - utilities, consumer staples, healthcare - have historically declined less than the broad index during downturns, while higher-beta, more cyclical sectors like technology, consumer discretionary, and small-caps tend to fall the hardest. This is the basis of defensive sector rotation, covered in depth in Cyclical vs. Defensive Stocks: A Sector Rotation Guide.

What Actually Helps Once You're In One

None of these require correctly predicting how deep or how long the decline will be - which nobody can do consistently:

• Keep contributing. Investors who stopped putting new money in near the 2009 or 2020 lows missed buying some of the cheapest shares of the entire cycle. A dollar-cost averaging plan that continues through a decline, rather than pausing until things "feel safe" again, is one of the most consistently cited advantages of a systematic approach.
• Define your exit before you need it. A trailing stop-loss or a straightforward stop order locks in a decision about how much downside you're willing to absorb on any single position, made when you're calm rather than during the worst week of the decline.
• Use alerts instead of watching the screen. A price alert at a key support level, a moving-average alert, or a portfolio-wide downside notification does the monitoring for you, so a bear market doesn't require sitting in front of a chart during its most volatile stretch. See How to Set Stock Price Alerts for the setup.
• Know the difference between a correction and confirmation you're in a bear. Not every 10% pullback becomes a 20%+ decline - most don't. Overreacting to every correction as if it's the start of a bear market is its own costly mistake.

Related Reading

• What Is a Bull Market? Definition, History, and How to Invest During One
• Every Major Stock Market Crash Since 1929
• Bull Traps and Bear Traps: Avoid False Breakouts
• Dead Cat Bounce Explained: How to Tell a Fake Recovery From a Real One
• Cyclical vs. Defensive Stocks: A Sector Rotation Guide
• Trailing Stop Loss Explained: How to Lock In Gains Without Capping Your Upside
• Dollar-Cost Averaging (DCA) Explained