Bull and bear markets

Investing glossary · Markets and instruments

A bull market is a sustained rise of 20% or more from a low; a bear market is a decline of 20% or more from a peak.

Definition

A bull market is a sustained period of rising prices, conventionally a gain of 20% or more from a recent low. A bear market is the opposite: a decline of 20% or more from a recent peak. The 20% thresholds are a convention, not a law of nature, and are most often applied to broad indices.

Bear markets are part of how markets work and historically they have been followed by recoveries, though timing and length vary widely. The same labels are sometimes used for individual stocks, where a fall of 20% from the high is a quick way to see whether a stock is "in a bear market" of its own.

Formula

Bear market: decline ≥ 20% from the latest peak. Bull market: rise ≥ 20% from the latest trough.

Measure from the latest peak (for bear markets) or latest trough (for bull markets) to the current price.

Worked example

Live ATLAS data, Oct 26, 2026

NVIDIA (NVDA) trades at $219.06. Its 52-week high is $243.37, which puts it 10% below that peak, while it stands 33% above its 52-week low of $164.27.

A fall of 20% or more from the high would be bear-market territory by the usual convention; a rise of 20% or more from the low, bull-market territory.

How ATLAS uses it

ATLAS tracks how far each stock is from its high and, for fallen stocks, estimates the odds of getting back with the Recovery tool.

Related in ATLAS: Stock analysis →Browse all ATLAS tools →

See it on a real stock

The example above uses these companies. Open their pages for the full numbers:

Frequently asked questions

Why 20%?

It is a widely used convention to separate ordinary pullbacks (around 10%) from deeper declines. There is no formal definition.

How long do bear markets last?

It varies. Some last a few months, others more than a year, and the recovery can take longer. History is a guide to the range, not a schedule.

Related terms

Put the idea to work on your own stocks

Open any company in ATLAS to see its fair value, its odds of rising and its risk numbers side by side.

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Not investment advice. ATLAS estimates are produced by statistical models from public data; they can be wrong and past performance does not predict future results. Consider your own situation before investing. Disclaimer

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