WebMD Health Corp. (NASDAQ:WBMD) stock has been a gauntlet for investors. One among a crowd of Web 2.0 growth stocks that have lost almost as much as they’ve gained, the company has been a risky bet since it went public in the Autumn of 2005. Today’s performance, an 18% jump in value since open, is attracting attention, but investors should be wary given past performance.

WebMD Health

Early today WebMD Health Corp. (NASDAQ:WBMD) said that it expects its first quarter earnings to be well ahead of the numbers Wall Street was looking for. The firm is forecasting earnings at the upper end of its previous forecast. With a rebound in momentum stocks already in the cards for the day, the upbeat guidance pushed the stock significantly upward before noon.

WebMD forward guidance shocks investors

The 18% jump in the value of WebMD Health Corp. (NASDAQ:WBMD) shares is enough evidence to suggest that investors really weren’t expecting this morning’s news. According to the company first quarter earnings, which are expected to be reported on April 30, will come in at the higher end of its guidance. The firm previously forecast EBITDA of $28.5 million to $30.5 million for the period.

Revenue in the three months is expected to come in at $130 million to $133 million, according to the company’s own numbers. By consensus analysts were looking for earnings of $29.7 million on revenue of $132 million for the three month period. The company also said that it expected its earnings and revenue to come in in the top half of its guidance for the full year 2014.

According to WebMD Health Corp. (NASDAQ:WBMD) 174 million people visited its websites during the first quarter. That number is up by almost a third since the same period in 2013. WebMD appears to be on track for a solid year, but the company is trading at a P/E of 137, a number that might, and should, scare away many investors.

WebMD stock continues to whiplash investors

Before today’s boost, stock in WebMD Health Corp. (NASDAQ:WBMD) had lost more than 4% of its value so far in 2014. The company’s high valuation, coupled with the cautious momentum of investors in the initial months of the year, sent its value down at a much higher rate than the wider market. Today’s gains leave the company up more than 135 for the year to date.

Despite the gains, the company is still 19% below the high it set at the end of April 2011, the last time that momentum stocks took a real bashing. WebMD Health Corp. (NASDAQ:WBMD) investors have to be careful about when they jump on the company’s stock. Since going public there have been a couple of major rises and falls, and a lot of volatility in between.