What Is a Bear Market? Rules, Causes, and Examples (2026)

A bear market is when a major stock index such as the S&P 500 or the Dow falls 20% or more from its most recent high. That single number is a convention rather than a law, and it is the line most investors check first when markets turn rough. Updated for October 2026.

Getting the definition right matters less than what it does to your behaviour. A 20% drop requires a 25% rise just to get back to where you started, which is why panic selling near a low costs far more than the decline itself. This guide covers what is a bear market in practice, what triggers one, how long they run, and how to think about a downturn without pretending you can time it.

The examples and figures below cover history rather than current market levels, and nothing here is personal investment advice. Rules, index definitions, and tax treatment differ by country, so check what applies where you live.

Key takeaways

• What it is: a decline of 20% or more from a recent high in a major index, measured peak to trough.
• How often and how long: roughly one every three to six years, an average decline near 34%, and a typical run of 11 to 14 months.
• What causes it: recessions, rising inflation and interest rates, weakening profits, credit stress, stretched valuations, and sudden shocks.
• What to do: hold a funded cash reserve, keep a diversified mix, keep contributing on schedule, and check whether your plan still matches your time horizon.

What Is a Bear Market? Definition and the 20% Rule

The rule of thumb is simple. Take the highest level a major index reached, measure the decline from that high to the eventual low, and if the difference is 20% or more, the market was in a bear market over that stretch. In practice people apply it to the S&P 500, the Dow Jones Industrial Average, the Nasdaq Composite, and plenty of other benchmarks including sectors, national markets, and single stocks.

The name comes from how the animals were described in old market commentary. A bull attacks by thrusting its horns upward, and a bear swipes downward with its paw, so rising markets were bull markets and falling ones were bear markets.

Worth knowing: the 20% figure is arbitrary. Nobody drew it out of a formula, and the same 20% threshold can mean something very different in an index that moved 3% the month before and something very different in one that fell 15% in six weeks. Some analysts define a bear market by behaviour instead, describing a period when investors are broadly risk-averse rather than risk-seeking. Most headlines still use the number because a number is easy to check.

The bull market side works the same way in reverse. A bull market is a sustained advance from a prior low, and the more careful version of the rule requires a rise of 20% or more to confirm one.

How Bull and Bear Markets Differ

Feature	Bull market	Bear market
Direction	Rising from a prior low	Falling from a recent high
Conventional threshold	Rise of 20% or more off the low	Decline of 20% or more from the high
Typical sentiment	Risk-seeking, optimism	Risk-averse, defensive
What gets bought	Growth, cyclicals, small caps	Defensive sectors, cash, quality bonds
What usually sells hardest	Defensives and long-duration bonds	High-multiple growth shares
Recurring pressure point	Valuations stretching too far	Rising rates squeezing future profits

One caveat on the table above. Sentiment and sector behaviour describe tendencies, not rules. In an inflation-driven downturn, value and mining shares can fall hard alongside everything else, and in a recession driven by falling demand, defensive sectors can be dragged down too.

What Does a 20% Decline Actually Mean?

It is a percentage change measured from a peak, not a number of percentage points. An index moving from 5,000 to 4,000 is down 20%. An index moving from 1,000 to 800 is also down 20%, and that second example is the one to hold on to, because both moves produce the same arithmetic problem on the way back up.

That is the asymmetry most retail investors miss. After a 20% fall you need a 25% gain to break even. After a 30% fall you need roughly a 43% gain. After a 50% fall you need a full 100% gain just to return to the starting line, which is why losses compound against you so quickly while gains only add up.

The 20% line is measured on any series you choose, and that choice changes the answer. A sector index can be in a bear market while the broad market is flat. A single stock can drop 40% in a rising market and never register on any index. Many commodity and mining investors watch a sector or a commodity benchmark instead of the S&P 500 for exactly that reason, so check which series your own holdings are measured against.

What Causes Bear Markets?

There is no single trigger. Declines usually come from a combination of a few of these, and historians argue endlessly about which one mattered most in any given episode.

1. Recession and slowing growth. Weaker demand means lower expected profits, and the market prices expectations forward. The 2007 to 2009 decline ran alongside a genuine contraction in economic activity.
2. Rising inflation and interest-rate increases. Higher rates push down the present value of future profits and raise the cost of borrowing, which hurts rate-sensitive sectors and highly valued growth shares first. The 2022 decline was driven mainly by this mechanism.
3. Weakening corporate profits. When reported earnings fall short of forecasts, analysts cut estimates, and the price adjusts downward even though the business itself is still operating normally.
4. Credit and financial stress. Spreads widen, funding gets harder to find, and lenders pull back. Trouble at a small number of institutions can spread fast when their counterparties hold similar assets.
5. Valuation compression. Prices rise faster than earnings for years, then the multiple shrinks back toward something more ordinary. The fall can be steep even when companies are still profitable.
6. Geopolitical shocks. Wars, sanctions, trade disputes, and sudden political changes hit supply chains and margins, and markets reprice uncertainty quickly.
7. Policy shocks and pandemics. Sudden shutdowns and emergency policy moves create gaps no model priced in. The February to March 2020 fall was the sharpest of that kind on record.
8. Loss of confidence. Once investors expect further declines, waiting to sell becomes its own reason to sell, and a rational reaction can feed an irrational spiral.

A word about valuation: a high price is not a cause on its own, and plenty of expensive markets have kept rising for years. Valuation becomes dangerous when it meets rising rates, slowing growth, or both at the same time.

How Is a Bear Market Different From a Correction?

A correction is the smaller cousin. The conventional marks are a decline of roughly 10% or more from a recent high, typically under two months, and corrections are far more frequent than bear markets. The distinction matters because the historical record treats them very differently.

Measure	Correction	Bear market
Decline threshold	Roughly 10%	20% or more
Average duration	Roughly 5 months	Roughly 11 to 14 months
Typical depth	10% to 15%	About 34% on average
Usual pattern	Shallow, quick, often within an uptrend	Long decline with rallies inside it
Recovery expectation	High, most end without recession	Historically complete, but the wait is long

Since the Second World War, bear markets have averaged roughly 14 months while corrections have averaged around 5. Counting the Dow back to 1900 gives a similar picture with about 33 bear markets in that span, which works out to something closer to one every three years. The wider estimates people quote, roughly one every six years, come from shorter post-war samples and different index definitions. Both numbers are defensible, which is why you will see both.

There is a practical test for which one you are in. If you keep hearing that a fall looks serious but it is only a correction, you are probably still inside the 10% to 20% band. Once an index crosses 20% and stays below it, the label changes and the recovery clock becomes the question that matters.

Two more terms get mixed in constantly. A bear market rally is a sharp bounce inside an ongoing decline, and it is not evidence that the decline has ended. A bear trap is a rally strong enough that investors treat it as a durable bottom, only to see prices fall again afterwards.

What Happens to Stocks and Other Assets During a Bear Market?

Stocks usually fall, but not evenly, and the damage depends on valuations and rate sensitivity. Companies with high growth expectations and little current profit tend to suffer more when rates rise, because their value sits further in the future. Established businesses with steady cash flow typically hold up better, though they fall too.

Bonds often behave differently from stocks, but not always. When the cause is slowing growth and falling inflation, government bonds frequently rise as investors move toward safety. When the cause is rising inflation, bonds can fall alongside equities, which is what made the 2022 decline unusual.

Precious metals, commodities, and currencies have their own patterns rather than a dependable safe-harbour role. Gold behaves as a real asset when inflation is the driving force and as a risk asset when real yields climb, which is why it fell during part of the 2022 downturn. Industrial commodities track manufacturing demand closely and often weaken in a recession. Mining and energy equities are leveraged versions of both the commodity and the equity market, so they typically fall harder than the metal or the oil they represent, and they can rally violently at a bottom.

None of these relationships is a guarantee, and none of them makes a downturn the time to reach for an asset nobody owns in good times.

How Can Investors Recognize a Bear Market?

The most reliable check needs only two numbers: today’s level of the index you care about, and its recent high. Divide the second by the first and you have the drawdown. If it is 20% or more, the index has met the conventional definition, whatever the commentary says that day.

Several other indicators give useful context, and no single one confirms a bear market on its own:

• Drawdown from the high. The defining measure, and the only one with a fixed number attached.
• Weakening breadth. If fewer and fewer stocks are making new highs while the index slides, participation is narrowing and the move is less healthy.
• Falling earnings estimates. Analysts cutting forward profit forecasts usually reflects something real in the economy.
• Rising volatility. Spikes in implied volatility show investors paying up for protection, and they often cluster near turning points rather than at the start.
• Credit conditions. Widening corporate and high-yield spreads suggest lenders see more risk, and credit tends to turn before equities do.
• Economic data. Contraction indicators, unemployment trends, and consumer confidence give the decline a macro cause rather than a purely technical one.

Bear markets also move through recognisable phases, and naming the phase tends to calm people down because it puts the experience in a sequence. The first phase is where prices fall from the high on deteriorating data while most investors still expect a pullback to end soon. The second is the arrival of bad news, falling profits, and rising unemployment, when the decline becomes obvious to everyone. The third is panic, where sentiment is dreadful, selling is disorderly, and valuations can look cheap on paper while continuing lower. The fourth is the decline that appears to bottom, marked by improving data, calmer sentiment, and rallies that hold up longer, though the market can still fall from there.

Longer-horizon bear markets are a separate category. A cyclical bear market runs months to a couple of years. A secular bear market stretches a decade or more with flat or disappointing total returns, and the Dow roughly traded in a narrow band from 1966 to 1982 without regaining its earlier highs in real terms. If you are a long-horizon investor, that distinction matters more than the day-to-day noise.

What Should Investors Do During a Bear Market?

Most of the useful advice here is unglamorous, which is why it gets ignored when headlines get loud. Take these as a checklist to run against your own plan rather than as a recommendation.

1. Check whether your plan still fits. A bear market matters mainly if you were counting on selling soon. If the money you need is years away, a downturn is mostly noise. The investors who get hurt are the ones whose timeline was always short and who treated it as long.
2. Hold a cash reserve for near-term needs. Forum consensus across places like Bogleheads and Canadian Money Forum has long been one to two years of expenses in cash or cash equivalents. That reserve removes the temptation to sell assets at the worst possible moment.
3. Review diversification honestly. Concentrated positions, including employer stock or a single sector, turn a market decline into a personal catastrophe. This is the moment to check whether your holdings are genuinely spread across asset types, sectors, and regions.
4. Keep contributing on schedule. Dollar-cost averaging continues to buy more units when prices are low, lowering your average cost. The arithmetic is simple: shares bought at 200 and falling to 150, then to 120, cut your cost basis per share each time. It also removes the need to make a call on timing, which is the actual advantage.
5. Rebalance rather than react. Rebalancing on a fixed schedule, or when an asset drifts far from its target weight, sells some of what has run up and buys what has fallen. That feels uncomfortable and is exactly the point.
6. Cut the noise. People describe checking a falling portfolio daily as its own risk, and it is a fair description. Deciding how often you look, in advance, makes the decision calmer later.
7. Know what you would do, before you have to. Write down the conditions that would genuinely change your plan, such as a shift in job security or a new financial goal. Without that list, every headline looks like a reason to act.

Two things to skip. First, any strategy whose main appeal is that it can win back losses quickly. Second, portfolios built around trying to predict the low. Repeated forum consensus on timing is blunt: most people lose more by trying to dodge declines than by riding them out, and being out of the market during a recovery is the cost that never gets billed to you.

Sequence-of-returns risk when you are drawing income

Near-retirees face a specific danger that workers do not. If you start withdrawing money from a portfolio just as it falls, you are selling more units at bad prices, and those units are the ones that would have recovered. Two portfolios with identical average returns can end up in completely different places depending on the order of returns.

A simple illustration: a 60 and 40 mix, one retiree withdrawing during a falling year when equities drop 30%, another withdrawing during a rising year. Same withdrawals, same long-run average return, very different ending balance. The first retiree sells into the decline and permanently reduces the base that had recovered.

The usual responses are to hold a larger cash or short-term bond buffer for a few years of spending, to keep flexible spending in mind when markets fall, or to delay a planned retirement. None of these are free, and each carries its own trade-off, which is why a conversation with a fee-only financial planner is worth more than any article during that stretch.

Strategies that bet on a decline come with real risk

Short selling, put options, and inverse exchange-traded funds all rise when markets fall, and all three are used by investors who expect a decline to continue. The catch is structural. Borrowing to short costs money, and daily-reset products lose value over time unless the move is large and quick enough to overcome that decay.

Take a product designed to deliver roughly the inverse of a daily index move. If the index falls 5% one day, the fund is built to rise about 5%. If it rises 5% the next day, it is built to fall about 5% that day. Starting at 100, the fund goes to 105, then to about 99.75, while the index ends its two-day round trip unchanged. Two days, no net move in the market, and a loss in the position. That is why these products are described as holding strategies for sharp declines, not long-term positions.

Short selling carries its own trap. The maximum a share can rise is unlimited, so the loss on a short position can grow far beyond what you expected, and you may be asked to cover at the worst price. Options avoid unlimited loss but add expiry, volatility, and timing risk, which is a lot of moving parts to get right during the worst weeks of a year.

Can Investors Tell When a Bear Market Has Ended?

Only afterwards. A bottom is confirmed by what happens next, so anyone claiming to have called one in advance is describing luck. That is not defeatism, it is the reason sensible plans avoid depending on the call.

Several developments tend to show up as conditions improve, and none of them confirms anything by itself:

• Economic data stops getting worse, and the labour market shows fewer signs of weakening.
• Market breadth widens, with more stocks taking part in the recovery than in the decline.
• Earnings estimates stop falling and begin rising again.
• Credit spreads narrow, meaning lenders become more willing to fund risk.
• Volatility falls back and investors stop paying up for protection.
• New highs begin holding, so rallies are no longer sold immediately.

Even with all six, prices can retreat again before continuing higher, which is why the historical pattern matters more than any signal. Every bear market on record has eventually been followed by a full recovery to the prior high, though the wait has stretched from under a year to more than two decades when measured in real terms after inflation. The 1929 crash is the extreme case. The Dow took until 1954 to regain its 1929 high in nominal terms, and longer once inflation is accounted for.

The practical conclusion is that recovery timing does not belong in a plan. What belongs in a plan is whether you can stay invested, and for how long, without needing to act.

Frequently Asked Questions

Conclusion

A bear market is a decline of 20% or more from a recent high in a major index, a convention that captures direction and mood without predicting duration. They arrive roughly every three to six years, average about 14 months, fall around 34% on average, and have always eventually been followed by a full recovery.

So the useful first action is small: write down what your money needs to do, what your time horizon is, and how much cash covers the near term. If a decline changes none of that, there is no decision to make, which is a far better position to be in than trying to guess the low.

Source: https://www.pgm-blog.com/what-is-a-bear-market/