What happened Shares of Weight Watchers International, Inc. (NYSE: WTW) jumped again last month as the company turned in a solid first-quarter earnings report and investor enthusiasm continued to build for the company's comeback. Image source: Weight Watchers According to data from S&P Global Market Intelligence, the stock jumped 26% in May. As the chart below shows, the stock got a boost after earnings on May 2, and continued to rise from there. WTW data by YCharts So what The weight-loss service saw a 16% increase in subscribers to 3.6 million, marking its sixth straight quarter of positive subscriber growth. Revenue was up 7%, or 9% on a constant-currency basis, to $329 million. On the bottom line, the company swung from a loss of -$0.17 per share a year ago to a profit of $0.16 a share, easily beating estimates at $0.04 a share. Chairman Ray Debbane called it a "very successful winter season" and said it solidifies the company's "return to growth." The stock continued to run higher over the duration as investors continued to buy into the turnaround story, which has been boosted by the company's partnership with Oprah Winfrey. Now what Weight Watchers also raised its guidance in the quarter, calling for full-year EPS of $1.40-$1.50 from a previous range of $1.30-$1.40. The stock is up a whopping 138% this year as investors have been encouraged by international expansion, subscriber growth, and the recent decision to name Mindy Grossman, the former head of the Home Shopping Network, as CEO. At this point, the stock may have exhausted most of its growth potential for the year, but if the company keeps on lifting its guidance, expect the stock to continue moving higher. 10 stocks we like better than Weight Watchers InternationalWhen 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 10 best stocks for investors to buy right now... and Weight Watchers International wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of June 5, 2017Jeremy Bowman has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.