Quality assurance provider Intertek Group (LSE: ITRK) was the best stock to buy in April, hindsight tells us. I didn’t see that coming. I’ve lost all interest in the FTSE 100 company as its shares have struggled for years. Suddenly, they’re up over 30% in a month. Does that make it the best stock to buy in May?

As a rule, I’d answer that question in the negative. Typically, that kind of spike is in response to a one-off piece of news or upbeat set of results, and it tends to bring out the profit takers. But can Intertek be the exception?

As I suspected, Intertek was responding to a positive Q1 trading update on 14 April. This showed revenue grew 6.7%, which reassured investors after soft 2025 results, published in March. The shares jumped 12% on the day.

Forget Intertek, take a look at London Stock Exchange Group

But this wasn’t the only factor driving Intertek. The rally extended towards the end of the month, after Swedish private equity firm EQT made several bids for the company, starting at $11.2bn.

Actually, I’m sorry, I’ll stop there. I never buying shares on takeover talk. If the deal goes through, the chance has gone. If it fails, new investors could take an instant hit as the shares retreat.

But another FTSE 100 share had a good April, and I think that this one is well worth considering today. Its name? Data analytics specialist London Stock Exchange Group (LSE: LSEG). It jumped 17% last month, smashing the FTSE 100 as a whole, which nudged up just 1.4%.

I can’t say definitely that LSEG, as it’s often called (or any other stock), is the best one to buy at present. But it posted a positive Q1 update, with total income up 9.8% year-on-year to a record £2.4bn. That’s good going, but hardly a surprise. Earnings per share have been racing along lately.

Earnings per share keep climbing

• 2025: EPS rose 14.4% to £3.29.
• 2024: EPS rose 10.1% to £2.88.
• 2024: EPS rose 8.65% to £2.61.

Like many data stocks, London Stock Exchange Group shares plunged in February over fears that artificial intelligence (AI) could offer its customers similar services at a reduced price. Investors are calming down. Why? While AI’s clever, we’re also learning its limitations. LSEG’s data can be relied upon, whereas AI makes mistakes. The data provider is also turning AI to its advantage, embedding it into its own systems to offer a better service to more customers.

I think London Stock Exchange Group can build on last month’s success, and maintain its momentum. It isn’t as cheap as it was, with a price-to-earnings ratio of just under 23. That’s low by its standard though. Over the previous decade, the group’s P/E ranged 35-74. Today, it looks like a bargain.

Despite the April hop, the London Stock Exchange Group share price is down 15% over the last 12 months, so I think there’s still a compelling long-term opportunity to consider here. For investors happy to hold for the long-term, and who aren’t too worried about AI.