The current U.S. bull market has now reached its fourth anniversary.
Since the S&P 500 bottomed in October 2022, the index has gained roughly 117%, making this the eighth-longest U.S. bull market since World War II.
That naturally raises one question:
Is the rally getting too old?
Not necessarily.
Bull markets rarely end simply because they have lasted a long time.
They usually end because the economic conditions supporting them change.
What Is a Bull Market?
A bull market generally describes a sustained period of rising stock prices, often associated with a gain of at least 20% from a previous market low.
Bull markets are usually supported by some combination of:
- rising corporate profits
- economic growth
- improving investor confidence
- easier financial conditions
- technological or productivity gains
The current rally has been heavily influenced by AI investment and strong technology earnings. Reuters notes that S&P 500 earnings are expected to rise more than 35% in 2026.
That matters because higher profits can justify higher stock prices.
Bull Markets Do Not Have an Expiration Date
Investors sometimes assume:
“Stocks have risen for years, therefore they must fall soon.”
That is not how markets work.
A four-year rally can continue if earnings continue growing and investors remain willing to pay current valuations.
Likewise, a young bull market can collapse quickly if:
- recession risk rises
- profits fall
- interest rates surge
- credit markets weaken
- valuations become unsustainable
Age alone tells investors very little.
What Actually Ends a Bull Market?
Bull markets usually become vulnerable when one or more major supports disappear.
A simple framework is:
Earnings + liquidity + valuation + confidence
If earnings keep rising, markets have fundamental support.
If interest rates rise sharply, valuations can come under pressure.
If credit becomes expensive, companies may invest less.
If investors lose confidence, expensive assets can reprice quickly.
Today, rising Treasury yields are one important risk. Reuters reports that higher borrowing costs and heavy AI-related capital spending are increasingly influencing investor sentiment.
Why Valuation Matters
Imagine two markets.
Market A
- strong earnings growth
- reasonable valuation
Market B
- strong earnings growth
- extremely high valuation
Both may have good businesses.
But Market B has less room for disappointment.
If investors already expect exceptional growth, even slightly weaker results can cause stock prices to fall.
This is why a strong economy does not automatically mean strong future stock returns.
Price paid matters.
Corrections Are Normal
A bull market does not mean stocks rise continuously.
Markets can experience:
- 5% pullbacks
- 10% corrections
- sharp sector rotations
and still remain in a broader upward trend.
Corrections can happen when investors reduce risk, bond yields rise or earnings expectations change.
The important distinction is between:
temporary volatility
and
a lasting deterioration in the investment environment.
Expected Return vs Risk
After a large rally, investors should not automatically sell.
But expected return should be compared with downside risk.
| Signal | What It Can Mean |
|---|---|
| Rising earnings | Supports stocks |
| Expanding valuations | Higher future risk |
| Rising bond yields | Greater competition for stocks |
| Narrow market leadership | Higher concentration risk |
| Strong breadth | Healthier rally |
| Weak credit conditions | Possible warning |
The strongest bull markets combine earnings growth with broad participation.
A market dependent on only a handful of companies can be more fragile.
The current U.S. rally remains heavily influenced by technology and communication-services stocks, increasing concentration risk even while overall earnings remain strong.
The Bottom Line
Bull markets do not die simply because they become old.
They usually end when the forces supporting them weaken.
The useful framework is:
earnings → liquidity → valuation → investor confidence
A four-year bull market can continue.
But as prices rise, investors should pay more attention to the return they are receiving for the risk they are taking.
The question should therefore not be:
“Is this bull market too old?”
It should be:
“Are earnings and economic conditions still strong enough to justify today’s prices?”
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