The term is used to define the crypto and NFT market when it experiences substantial growth and there is positive investor sentiment in the market.
The Long Explanation
It refers to a period of time when the demand for crypto and NFTs is higher than the supply, enthusiasts are buying tokens, holders are expanding their portfolio, and prices are on a rise.
During a bull market, NFT investors feel optimistic (bullish) and tend to invest more in NFTs, which in turn causes the prices to increase further.
Of course, even in NFTs, a bull market doesn’t last forever. Unforeseen triggers like, say a pandemic, unfavourable regulations, etc. can bring down investors’ confidence, and this, in turn, can take the market on a downward spiral and into a period called a bear market.