Let’s explore the biggest winners of 2026 so far, and whether there might be even more growth on the horizon for the top contender.

Explosive returns

In order of share price gains since the start of January, the best performing S&P 500 stocks are:

1. SanDisk Corp (NASDAQ:SNDK) – up 132%.
2. Moderna – Up 83%.
3. Texas Pacific Land Corp – Up 75%.
4. Generac Holdings – Up 51%.
5. Corning – Up 48%.

Delivering double-digit returns across an entire year can often be a challenge for many large-cap companies. So to see these businesses deliver such exceptional performance before the first quarter has even ended is undeniably impressive.

For reference, a £10,000 investment into an S&P 500 index fund at the beginning of 2026 is now worth around £9,880. But stock pickers smart enough to allocate this capital evenly across this basket of five US stocks are now sitting on roughly £17,780!

Of course, past performance doesn’t guarantee future returns. So blindly investing in these early winners, expecting them to continue outperforming, could backfire quite painfully.

With that in mind, let’s take a closer look at SanDisk.

Investigating SanDisk

SanDisk hasn’t been a public company for very long, having only joined the stock exchange in February 2025 following its spin-off from Western Digital.

However, despite its short tenure as a standalone business, the data storage device enterprise has delivered a jaw-dropping 1,600%+ return since its IPO.

The company specialises in NAND memory storage devices. Following a supply glut throughout 2024, SanDisk, along with Samsung and other NAND specialists, deliberately curtailed production capacity to stabilise prices.

However, skip ahead to late 2025, and demand’s skyrocketed. With hyperscalers drastically ramping up their artificial intelligence (AI) infrastructure spending and replacing traditional hard disk drives (HDDs) with faster NAND solid-state drives (SSDs) to handle AI workloads, the supply/demand dynamics have flipped.

As such, in its latest quarterly earnings report, SanDisk’s revenue jumped 61% year on year, gross margins expanded from 32.5% to 51.1%, and operating profits skyrocketed 386% from $233m to $1,133m.

With management guiding for even more gross margin expansion to as high as 67% in the next quarter, the growth journey for SanDisk shares looks far from over.

Taking a step back

As we’ve already seen in recent years, NAND memory pricing’s notoriously cyclical. And looking at its original parent company, Western Digital’s suffered multiple 50%+ multi-year declines.

If AI capex slows, the explosive momentum and excitement behind SanDisk shares could follow.

Alternatively, even if hyperscalers continue their spending spree, higher production volumes from rivals like Samsung could result in a supply surplus, sending NAND prices firmly in the wrong direction – something that’s happened multiple times in the past.

Overall, there’s a lot of understandable excitement surrounding this sector today. But with the share price already skyrocketing, it seems a lot of the anticipated future growth’s already priced in. As such, investors may be better off looking at other S&P 500 stocks for sustainable growth opportunities.

The post Here are the best-performing S&P 500 stocks in 2026 so far appeared first on The Motley Fool UK.

A hyper-growth firm

I’m referring to SanDisk Corp (NASDAQ:SNDK). It’s a US tech company focused on flash memory storage solutions. On the face of it, that might not sound that exciting (or relevant). However, its products and solutions are widely used in AI infrastructure and data centres, as well as with enterprise and cloud storage clients. Given the huge growth in these areas at the moment, the penny is starting to drop as to why SanDisk is doing so well right now.

Investors are factoring in massive demand for data storage driven by AI training and inference workloads. The massive datasets involved require high-speed flash storage. Right now, there is an industry-wide shortage of certain products, which has supported higher pricing and stronger margins, as SanDisk becomes a power player.

Financial results drive gains

It’s not just speculation regarding AI demand. At the end of last month, the US stock rocketed 25% higher on the day it released the latest quarterly results. It posted a profit of $803m, up from $104m a year earlier. That goes some way to show the explosive growth the company is experiencing.

The CFO said at the time that the company still cannot keep up with the demand. This highlights to me that there is scope for further growth in revenue and profit this year and beyond as it scales up.

Taking a breather

Over the past year, the stock is up 1,500%. It is now in the S&P 500, with the publicity recently another factor helping to drive momentum. I can see why some feel it is a no-brainer buy, given its role in the AI theme. If AI adoption continues to increase, SanDisk is well-positioned to profit from it. Even with the rise, the $85bn market cap is still relatively small compared to other tech stocks.

However, there are risks involved. For a start, the stock price has appreciated dramatically. This could mean much of the future growth may already be taken for granted. If growth slows, the stock could retrace sharply, given the high benchmark now set. Furthermore, the company has a heavy reliance on Asian supply chains and joint ventures. This introduces a host of risks including geopolitical tensions and production disruption.

I cannot call it a complete no-brainer, because there are factors outside of all of our controls that could mean the stock underperforms this year. But even with the concerns, I do think it’s one of the best S&P 500 stocks to consider buying right now.

The post Is this the best no-brainer S&P 500 stock to consider buying now? appeared first on The Motley Fool UK.