A bull market in crypto refers to a period of rising prices and market optimism, where the value of cryptocurrencies, in general, experiences a prolonged and significant increase. During a bull market, investors and traders are more likely to buy cryptocurrencies, leading to a further increase in prices. Bull markets are often characterized by a high level of optimism, increased trading volume, and a decrease in volatility. It is the opposite of a bear market, where prices are falling, and market sentiment is generally pessimistic.