What Is a Bull Market?
A bull market is an extended stretch in which prices trend upward and investor confidence builds on itself. The most common technical definition for equities is a rise of at least 20 percent from a recent trough, typically measured on a broad index like the S&P 500.
The term applies beyond stocks: bonds, commodities, housing, and even individual sectors can experience bull markets. The name comes from the way a bull attacks by thrusting its horns upward, a mirror image of the bear's downward swipe.
How Bull Markets Behave
Bull markets usually begin when pessimism is deepest, often while the economy still looks weak, because markets price in recovery before it fully arrives. Early gains are driven by cheap valuations, then by improving corporate earnings, and in late stages by expanding multiples and speculative enthusiasm.
They are rarely smooth. Corrections, defined as pullbacks of 10 percent or more, occur regularly within long bull markets without ending the broader uptrend, which makes distinguishing a correction from a new bear market one of the hardest judgment calls in investing.
Example
Suppose an index bottoms at 3,000 after a downturn. Once it closes at 3,600, a 20 percent gain from the low, the move is commonly labeled a new bull market. If the rally continues to 6,000 over several years, an investor who put in 10,000 dollars at the bottom would have doubled their money to 20,000 dollars before dividends.
History offers dramatic cases: the U.S. bull market that began in March 2009 ran for nearly 11 years, with the S&P 500 gaining roughly 400 percent before the 2020 pandemic ended it.
Why It Matters
Most long-term wealth in equities is created during bull markets, and missing their strongest early months is one of the costliest mistakes market timers make. Bull markets also loosen financing conditions, fueling IPO windows, M&A activity, and heavy deal flow across investment banking.
Understanding where the market sits in its cycle shapes positioning for traders and asset allocators alike, and the bull versus bear framing is the everyday shorthand of financial commentary.
