Is the bullish run for Red Hat (NYSE: RHT) over?

After reaching a 52-week high of $62.75 earlier this month and seeing its share nearly double from a 52-week low of $31.77, Red Hat shares took a hit on Wednesday.

Stock in the largest seller of products and serviced based on the open-source Linux operating system fell the most in five months after an analyst at Piper Jaffray & Co. projected a slowdown in billings growth.

Billings, a predictor of revenue, “could lack the explosiveness seen in the fourth quarter,” said Mark Murphy, an analyst at Piper Jaffray in San Francisco, in a note today. “The macroeconomic climate has degraded since Red Hat issued guidance in March.”

As Red Hat, which is based in Raleigh, N.C., works to expand its offerings for customers who want to access data over the Internet using so-called cloud computing, the company is also dealing with the impact of fluctuations in foreign currencies and the European debt crisis, Murphy said. He has an overweight rating on shares, the equivalent of a buy recommendation, and a target price of $63.

“While billings growth should decelerate this year, we continue to believe Red Hat is favorably positioned into the secular trends of cloud computing, open source, virtualization and unstructured data, and should continue gaining market share,” Murphy said.

The shares of Red Hat declined 5.1 percent to $53.43 at 10:43 a.m. in New York, for the biggest intraday decline since Dec. 21. The stock had climbed 36 percent this year before Wednesday.

By 1 p.m., shares were lower at $52.97, or nearly 6 percent.

Shares did rally before the close to end the day at $54.43, down 3.7 percent or $1.87 on the day.

Some 3.5 million shares traded hands, much heavier than the daily average of 2.1 million.

The sellout resumed after hours, falling 69 cents.