In the investment world, the term bear market refers to a market that experiences a significant and prolonged decline in prices. Bear markets are characterized by negative sentiment among investors, where fear and pessimism dominate. The price decline in a bear market is usually more than 20% from the previous peak, and this condition can last for several weeks, months, or even years.

Bear markets are often thought of as the opposite of bull markets, where asset prices tend to rise. In crypto markets, which are known for their volatility, bear markets can occur more frequently than in traditional markets like stocks or bonds. Bear markets reflect not only a drop in price, but also a decrease in trading volume, low investor interest, and often a large capital outflow from the market. For example, Bitcoin's price drop in 2018, where it fell from around $20,000 to $3,000, is considered one of the biggest bear markets in crypto history.