Defining the bull
A bull thrusts upward with its horns — and that image captures what a bull market is: prices rising, confidence growing, and capital flowing in. The standard definition is a gain of 20% or more from a recent trough, sustained over a meaningful period. Not every sharp rally qualifies; brief "dead cat bounces" in otherwise falling markets are not bull markets.
What fuels a bull market?
No single factor creates a bull run, but the ingredients are usually familiar: a growing economy with rising employment, corporate earnings beating expectations, low or falling interest rates (which make equities more attractive versus bonds), government stimulus, or a new technological wave creating genuine economic expansion. The longest US bull market — 2009 to 2020 — was propelled by near-zero interest rates and a decade of tech-sector dominance.
The psychology of a bull market
Bull markets are as much about sentiment as fundamentals. As prices rise, more investors pile in, driving prices higher still — a self-reinforcing loop. This optimism can overshoot reality, leading to stretched valuations where investors pay prices that only make sense if everything goes perfectly. That is when a bull market becomes fragile and vulnerable to reversal.
Spotting a bull market getting long in the tooth
No bell rings at the top, but warning signs include: price-to-earnings ratios well above historical averages, widespread overconfidence, companies with no profits being valued like empires, and IPO frenzies for anything with "tech" in the name. The dot-com peak of 2000 and the 2021 meme-stock frenzy both displayed these hallmarks before sharp reversals.
"Markets can remain irrational longer than you can remain solvent." — John Maynard Keynes
What this means for you
Bull markets reward patience and participation. The mistake most investors make is waiting for the "perfect" entry point — which never comes. The practical approach: start investing, stay diversified, and rebalance as valuations stretch. Trying to time the top is a fool's errand; time in the market consistently beats timing the market.