2 Top Stocks Long-Term Investors Should Buy in May

There is an old adage that says to "sell in May and go away." This is a strategy of selling stocks this month and then returning to the market in November after the summer, because there is a belief that stocks underperform during this period.

While there is some merit to stocks underperforming during the summer months, this strategy has worked only 22 times in the last 53 years, and investors would have missed out on some big gains last year. The better move is to stay invested, and there are still some great buying opportunities out there. Let's look at two growth stocks to buy now for the long term.

Amazon: Mounting momentum

One of my favorite stocks to buy right now is Amazon (NASDAQ: AMZN). The company has been running on all cylinders with both its cloud computing and e-commerce businesses, and it has strong growth opportunities ahead. Meanwhile, on a forward price-to-earnings (P/E) basis, the stock is cheap (31.5 times multiple) from both a historical perspective and compared to brick-and-mortar peers Walmart and Costco, which trade at over 40 times multiples.

Within its e-commerce business, Amazon continues to see strong operating leverage driven by the efficiency gains it is seeing from its leadership in robotics and artificial intelligence (AI). This was on full display in the first quarter (Q1) of 2026 when its North American operating income surged 43% despite a 12% increase in sales. The company is also seeing strong momentum in its ad business, with revenue climbing 24%. Looking ahead, the company has a big opportunity as it opens up its logistics network to channels outside its e-commerce website, including high-margin, business-to-business transport.

Meanwhile, Amazon Web Services (AWS), its most profitable segment, has been seeing its revenue growth accelerate, hitting 28% growth in Q1. That was its highest level of growth in nearly four years, and the company is investing aggressively in data center infrastructure to add capacity to capture the huge opportunity in front of it. With deals with Anthropic and OpenAI in place and its heavy investment spending, growth should continue to accelerate throughout the year.

Meanwhile, the company's in-house chip business is a revenue driver and helps give it a cost advantage. Amazon recently revealed that this is a $20 billion run-rate business, or about $50 billion when including internal use. The company's Trainium AI accelerators help power a large data center dedicated to Anthropic, while Meta Platforms recently entered into a deal for Amazon's Graviton central processing units (CPUs) to support the social media giant's agentic AI efforts.

Between Amazon's AI opportunities and the huge operating leverage it is seeing in its e-commerce operations, this is a top stock to buy in May.

Image source: The Motley Fool.

Shopify: Buy the dip

Following its sell-off earlier this month, Shopify (NASDAQ: SHOP) is another top e-commerce stock I'd jump on right now. Unlike Amazon, which has a huge platform where it sells both first-party and third-party merchandise delivered by its huge logistics network, Shopify provides a software-as-a-service (SaaS) platform that allows merchants to run both their online and offline businesses.

The company's core business has long been small and medium-sized (SMB) merchants, but today its platform also handles the back-end for large retailers and brands. It's also expanded its solution into the business-to-business (B2B) arena, as well as offline. And it has a strong international presence, with Europe being a big growth driver for the company.

Shopify generates revenue through a combination of selling its software platform along with offering payment processing and other merchant solutions. It has been achieving a higher attach rate for its payment processing services, which help it grow alongside its customers. Meanwhile, the company has a big potential growth driver with agentic commerce, as its Shopify catalog serves as the foundation of the universal commerce protocol (UCP) it co-developed with Alphabet. With AI agents needing trustworthy, structured data to search through to find items in stock and correctly priced, Shopify is positioned to be one of the big winners of this shift moving forward.

With the stock now trading at a forward price-to-sales ratio of below 8 based on 2027 analyst projections and growing revenue around 30%, this is now a great time to buy the stock for the long term.

Geoffrey Seiler has positions in Alphabet, Amazon, and Meta Platforms. The Motley Fool has positions in and recommends Alphabet, Amazon, Costco Wholesale, Meta Platforms, Shopify, and Walmart. The Motley Fool has a disclosure policy.