The first half of 2026 is officially in the books.

The S&P 500 gained just over 9%.

The Dow Jones Industrial Average climbed just under 9%.

The Russell 2000 surged more than 21%.

But the headline numbers only tell part of the story.

Here's what really mattered during the first six months of the year – and what I think it means for the second half.

AI Still Ruled The Market

If you want to understand the first half of 2026, simply look at the list of the market's biggest winners.

• Sandisk (SNDK): +828%

• Micron (MU): +304%

• Intel (INTC): +290%

• Western Digital (WDC): +268%

• Marvell (MRVL): +247%

• Seagate (STX): +243%

• Dell (DELL): +238%

• Corning (GLW): +190%

• Applied Materials (AMAT): +183%

• Advanced Micro Devices (AMD): +171%

All ten of the best-performing stocks in the S&P 500 are directly tied to semiconductors, memory, AI infrastructure, or the hardware powering the artificial intelligence boom.

So while investors continue debating whether AI is overhyped, know that the companies supplying the picks and shovels continue ticking higher.

The Biggest Losers Tell A Story Too

The bottom of the leaderboard was just as revealing.

• Intuit (INTU): -60%

• CoStar Group (CSGP): -57%

• Boston Scientific (BSX): -55%

• Cognizant (CTSH): -54%

• Accenture (ACN): -54%

• The Trade Desk (TTD): -54%

• Gartner (IT): -48%

• Insulet (PODD): -46%

• Lululemon (LULU): -46%

• Workday (WDAY): -44%

These companies don't have much in common at first glance.

But several of them do.

Accenture, Cognizant, Workday, Gartner, and Intuit are all businesses whose value is tied to knowledge work, enterprise software, or selling human expertise.

Investors are beginning to ask an uncomfortable question: What happens when AI starts doing more of that work?

That doesn't mean these are bad companies.

It means the market is reassessing which businesses will benefit most from the AI revolution and which ones could see their business disrupted by it.

The Rally Finally Broadened

One of the most encouraging developments during the first half came in June.

After months of the rally being concentrated in a handful of semiconductor stocks, market leadership finally began to broaden.

Financials started participating.

Healthcare joined the rally.

Small caps surged too.

The Russell 2000 ended the first half more than 21% higher, putting the index on pace for its best first-half performance since 1991.

Granted, even that small-cap rally was heavily influenced by AI.

Nine of the ten best-performing stocks in the Russell 2000 are tied to artificial intelligence or semiconductors.

But investors are no longer just buying just the Magnificent Seven and a handful of chipmakers.

They're buying the broader AI ecosystem.

That's a much healthier market than the one we started the year with.

History Still Favors The Bulls

Through Friday, the S&P 500 had already recorded 24 new all-time highs during the first half of the year.

That's among the 20 strongest first halves since World War II.

And history suggests those gains often continue.

During the previous top-20 first halves, the S&P 500 gained an additional 6% during the second half of the year and finished higher around 80% of the time.

History never guarantees future returns.

But this is certainly an encouraging statistic.

My Biggest Takeaway

If the first half of 2026 proved anything, it's that the AI boom is proving much broader than almost anyone expected.

The winners are no longer confined to Nvidia and a handful of semiconductor companies.

They're spreading throughout the rest of the market.

That's exactly what you want to see during a bull market.

Leadership is expanding.

The economy is holding up.

And history suggests strong first halves often lead to strong second halves.

Nobody knows what the next six months will bring.

But after the first half we've just witnessed, I'm optimistic the market still has room to climb.