What happened Shares of research and advisory giant Gartner (NYSE: IT) jumped 18.4% in May, according to data from S&P Global Market Intelligence. The catalyst behind the pop was the company's release of a strong first-quarter report, which included a raise in full-year revenue and earnings guidance. For context, the S&P 500 returned 0.7% last month. Gartner is solidly outperforming the market so far this year after underperforming last year. In 2021, the stock is up 44.2% through June 7, while the S&P 500 has returned 13.3% over this period. In 2020, Gartner stock eked out a gain of 4%, while the broader market returned 18.4%. Image source: Getty Images. So what On May 4, shares of Gartner surged 14.2% following the company's release of its first-quarter results. Revenue rose 8.4% (5.7% in constant currency) to $1.1 billion, driven by contract value growth in the healthcare and technology industries. Net income according to generally accepted accounting principles (GAAP) was $164 million, or $1.84 per share, more than double the year-ago period's net income of $75 million, or $0.83 per share. Adjusted for one-time items, earnings per share (EPS) soared 67% year over year to $2. That result crushed the Wall Street consensus estimate of $1.05. In the earnings release, CEO Gene Hall commented, "We had an outstanding start to the year with strong growth in contract value, revenue, EBITDA [earnings before interest, taxes, depreciation, and amortization], and free cash flow." Data by YCharts. Now what Due to its better-than-expected results in the first quarter, the company raised its full-year guidance. It now expects revenue to grow at least 10% year over year to at least $4.51 billion, up from its prior outlook of revenue growth of at least 6%. It also guided for adjusted EPS of at least $6.25, which represents growth of at least 28% year over year. This is a huge increase from its prior outlook of adjusted EPS of $4.10, or a decline of 16%. On the earnings call, CFO Craig Safian broke down management's full-year revenue growth expectations for its three segments. It expects research revenue of at least $3.94 billion, or growth of at least 9.2%. Conferences revenue is projected to be at least $170 million, or growth of at least 42%, and consulting revenue is expected to rise at least 6.4% to land at a minimum of $400 million. Gartner stock is worth putting on your watch list. The company has a track record of easily beating earnings expectations and generates considerable free cash flow. 10 stocks we like better than GartnerWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Gartner wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 7, 2021 Beth McKenna has no position in any of the stocks mentioned. The Motley Fool recommends Gartner. The Motley Fool has a disclosure policy.Source