The 15 Stocks Driving the S&P 500's Gain in 2026

The S&P 500 is up 5.7% in 2026, and the contributor list is meaningfully wider than the past few years. That said, nearly every name doing the heavy lifting is plugged into the same theme: AI infrastructure.

Alphabet Takes the Crown

The single biggest engine of this year's rally is Alphabet (GOOGL).

The stock has contributed 1.27 percentage points to the S&P 500’s return all by itself. That is more than 20% of the index's return from a single name. 

Google Cloud demand is booming, Gemini is gaining traction, and the market is starting to give Alphabet credit for its custom AI chips—TPUs—which are now viewed as a legitimate alternative to Nvidia GPUs.

Alphabet and Nvidia are now the two most valuable companies in the world, with Alphabet having recently leapfrogged Apple for the number two spot.

The Other AI Heavies

Broadcom (AVGO) sits in second place at 0.6 percentage points, off an average index weight of just 2.8% this year. Broadcom is Alphabet's design partner on the TPUs and is working with OpenAI and Meta on their custom chips as well. 

Amazon (AMZN) takes third at 0.58 percentage points. AWS demand has accelerated and its custom chip program is gaining traction as well.

Nvidia (NVDA) comes in fourth at 0.56 percentage points, basically in line with its 7.7% average weight. The stock is still a big driver for the market, but it isn't dominating the way it did the past few years.

Punching Way Above Their Weight

After Nvidia come a long list of names punching way above their weight.

Intel (INTC) has averaged just 0.39% of the index but has contributed 0.47 percentage points of return, about 8% of the index total. The stock more than doubled in April alone and is up 156% on the year. 

CPU demand from AI inferencing workloads has been surging, and the market is starting to believe that Intel's foundry turnaround might actually work.

Micron (MU) has delivered 0.45 percentage points off a 0.77% weight, lifted by the boom in high-bandwidth memory, or HBM. HBM is the specialized memory that sits right next to GPUs in AI servers and feeds them data fast enough to keep them busy. Demand has been outstripping supply for over a year, and Micron is one of only three companies in the world that makes it.

Advanced Micro Devices (AMD) is in the same neighborhood at 0.4 percentage points on a 0.63% weight, lifted by demand for both its AI accelerators and its server CPUs.

The Non-AI Standouts

Exxon (XOM) is one of two top contributors to the S&P 500’s return this year with no AI angle at all. The oil giant has added 0.26 percentage points, lifted entirely by the spike in oil prices following the U.S./Israel/Iran war. Walmart (WMT) is the only other major non-AI stock among the top 15 contributors. 

Beyond those two, the AI thread keeps running through the rest of the contributor list. Caterpillar (CAT) and GE Vernova (GEV) are both data center power plays. 

SanDisk (SNDK) and Western Digital (WDC) cover the memory and storage angle. Applied Materials (AMAT), Lam Research (LRCX), and Texas Instruments (TXN) are tied into the semiconductor capex cycle.

Not Everyone Is Along for the Ride

The top 10 stocks have contributed 5.1 percentage points to the S&P 500's return this year, and the top 20 have contributed 6.5 percentage points. 

The top 20 contribution exceeds the index's 5.7% return because plenty of other names are dragging it down, offsetting the winners.

Microsoft (MSFT) has been the single biggest drag, lopping off nearly a full percentage point of return on its own. Despite being heavily involved in AI through its Azure cloud computing division and its hefty investment in OpenAI, investors are increasingly worried that AI could end up disrupting Microsoft's bread-and-butter software business.

In addition to Microsoft, other big detractors from the index’s return include Tesla (TSLA) at 0.35 percentage points, Eli Lilly (LLY) at 0.19, Meta (META) at 0.18, and Palantir (PLTR) at 0.16.