Archive · 12 Oct 2026
AI-Fueled Bull Market Turns Four With Room to Run
The U.S. stock market has been rising for four years.
The S&P 500, a group of many large companies, is up nearly 120% since the rise began.
Artificial intelligence has helped push stocks higher, especially shares in companies that make computer chips and other technology.
Investors have put a lot of money into building AI.
Some experts think the market could keep rising, and historical bull markets often last longer than four years.
But the gains are concentrated in a small number of large tech companies.
High oil prices, inflation worries and shaky bond markets could cause trouble.
Experts are watching to see whether more kinds of stocks begin to rise too.
The S&P 500 bull market began after the index closed at 3,577.03 on October 12, 2022, and has since risen nearly 120%.
The rally has produced 123 record closing highs and added nearly $40 trillion in market value.
The launch of ChatGPT and surging investment in AI helped drive gains, with Nvidia and other major technology companies leading.
Market concentration has increased: the 10 largest S&P 500 stocks account for about 40% of the index’s roughly $70 trillion value.
Analysts see potential for further gains but cite risks including high oil prices, volatile bond markets, inflation and narrow market participation.
- Who
- Investors, U.S. companies and analysts including Ryan Dietrick, Adam Turnquist and Nancy Tengler.
- What
- The S&P 500’s four-year bull market, driven substantially by technology and AI-related gains.
- When
- The bull market began on October 12, 2022; the article marks its fourth anniversary week.
- Where
- U.S. stock markets, particularly the S&P 500.
- Why
- AI investment and strong technology-company performance helped drive the rally; the article also cites broader market gains and profit growth.
Reasons for further gains
Risks to the rally
Bull-market durability
Reasons for further gains
Ryan Dietrick notes that all five major bull markets of the past half-century that reached a fourth year also reached a fifth; Nancy Tengler sees room for gains into the fourth quarter and next year.
Risks to the rally
The article warns that high crude prices, volatile bond markets and creeping inflation risks could weigh on stocks.
Market breadth
Reasons for further gains
A broader expansion in market participation could help confirm that gains are durable, and some analysts see more stocks joining the rally.
Risks to the rally
Technology has driven nearly all benchmark gains since the start of summer, and analysts say continued narrow participation is a key test.
AI-driven valuations
Reasons for further gains
The article points to strong profit growth and a lower S&P 500 forward price-to-earnings multiple—about 19.5 compared with more than 22 in January—as supportive factors.
Risks to the rally
The rally’s reliance on AI and a handful of large technology stocks raises concerns about a possible bubble and the risk of a sharp reversal.
- Bull market start
- October 12, 2022, when the S&P 500 closed at 3,577.03
- S&P 500 gain
- Nearly 120% over four years
- Nasdaq Composite gain
- More than 165% over the same period
- Record closes
- 123 new S&P 500 closing highs during the bull market
- Market value added
- Nearly $40 trillion
- Top 10 S&P 500 stocks
- About 40% of the index’s roughly $70 trillion market value
- AI investment estimate
- Expected to exceed $1 trillion in new cash this year; Goldman Sachs estimates as much as $7 trillion globally by the end of the decade