What Is a Bull Market vs Bear Market?

The Short Answer

A bull market is a sustained period of rising asset prices, typically defined as a 20% or greater rise from a recent low, accompanied by broad investor optimism. A bear market is the mirror image: a 20% or greater decline from a recent high, accompanied by pessimism and falling demand. The terms apply to individual stocks, sectors, indices, or entire asset classes like crypto.

The 20% threshold is a convention, not a law of physics, but it's the one most financial media and index providers use to mark the transition from a normal pullback into a defined trend regime.

What Defines a Bull Market

• Price trend: Higher highs and higher lows over months or years
• Sentiment: Optimism, rising risk appetite, expanding valuations
• Breadth: Most stocks or sectors participating, not just a handful of leaders
• Economic backdrop: Often (not always) coincides with GDP growth, low unemployment, and accommodative monetary policy

Bull markets tend to be long and gradual. The average post-WWII U.S. bull market has lasted roughly 4-5 years, climbing in a slow grind punctuated by shorter corrections (10% pullbacks) that don't break the underlying uptrend.

What Defines a Bear Market

• Price trend: Lower highs and lower lows, typically a 20%+ drop from the peak
• Sentiment: Fear, risk aversion, falling valuations
• Breadth: Widespread declines across sectors, with defensive assets (bonds, cash, gold) outperforming
• Economic backdrop: Often coincides with or precedes a recession, tightening monetary policy, or a credit event

Bear markets are typically shorter but sharper than bull markets — historically averaging under two years, with the steepest losses often concentrated in a few weeks or months (e.g., 2008, March 2020).

Bull Market vs Bear Market at a Glance

Factor	Bull Market	Bear Market
Price direction	Higher highs, higher lows	Lower highs, lower lows
Typical trigger	20%+ rally from a low	20%+ decline from a high
Duration	Years (gradual)	Months to ~2 years (sharper)
Investor sentiment	Greed, FOMO, risk-on	Fear, capitulation, risk-off
Volatility	Generally lower	Generally higher (VIX spikes)
Best-performing assets	Growth stocks, small caps, crypto	Cash, bonds, defensive sectors, gold
Volume pattern	Steady, rising on up days	Spikes on down days (panic selling)

How to Tell Which One You're In

No single indicator confirms a regime change in real time — by the time the 20% threshold is officially crossed, a meaningful move has already happened. Traders instead watch a combination of signals:

1. Moving averages: Price sustained above the 200-day moving average is a common bull-market proxy; sustained below it flags a bear market. See our guide on the golden cross and death cross for how this crossover is used as a regime signal.
2. Breadth measures: Are most stocks participating in the move, or is it concentrated in a handful of names?
3. Volatility: A rising VIX or a sharp increase in average true range often accompanies bear-market transitions.
4. Credit spreads and yield curves: Widening corporate credit spreads frequently precede equity bear markets.

How Trading Approach Should Differ

In a bull market, trend-following and buy-the-dip approaches tend to be rewarded because pullbacks are usually shallow and temporary. Position sizing can lean slightly more aggressive, and holding periods can extend, since the underlying trend is doing most of the work.

In a bear market, the same buy-the-dip instinct is far more dangerous — declines can be deep, fast, and prone to sharp counter-trend "bear market rallies" that trap buyers before the downtrend resumes. Risk management tightens: smaller position sizes, wider awareness of drawdown, and a bias toward capital preservation over chasing upside. Short selling and hedging (see short selling mechanics) become more relevant tools, though both carry their own risks that amplify in volatile conditions.

Common Misconceptions

• A single down day isn't a bear market. Normal volatility includes regular 5-10% pullbacks within an ongoing bull market. The 20% threshold exists specifically to separate noise from trend change.
• Bear markets don't move in a straight line down. Some of the sharpest single-day rallies in market history have occurred inside bear markets, which is exactly what makes them dangerous to trade from the long side.
• The label is retrospective as often as it is predictive. Analysts frequently only agree a bear market started weeks or months after the fact, once the 20% decline is confirmed.

Summary

A bull market is a rising-price, optimism-driven regime; a bear market is a falling-price, fear-driven regime, conventionally marked by a 20% move from a recent extreme. The distinction matters less for the label itself and more for the shift in behavior it should trigger: trend-following and larger position sizing fit a bull market, while capital preservation, smaller size, and hedging fit a bear market. Reading the regime correctly — using moving averages, breadth, and volatility together rather than any single signal — is a precondition for choosing the right strategy at the right time.

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Related reading:

• Golden Cross / Death Cross Moving Average Strategy — the most widely used technical signal for bull/bear regime shifts
• Position Sizing: How to Calculate How Much to Risk Per Trade — adjusting risk per trade across market regimes
• Short Selling Explained: Mechanics and Risks — how traders position for bear markets
• Crypto Market Cycles Explained — how bull/bear regimes play out in crypto specifically