NEW YORK (TheStreet) -- Shares of Noble Energy  (NBL) are down by 1.82% to $35.62 on Thursday afternoon, as the price of oil continues to slip.

Crude oil (WTI) is lower 0.48% to $49.32 per barrel and Brent crude is declining by 0.6% to $49.44 per barrel, CNBC reports.

After hitting a $50 per barrel milestone early this morning, oil prices then reversed their gains and slid the rest of the day. The fall is seen as a balancing point for oil prices and traders say it is a "buy opportunity," the Wall Street Journal reports.

The recent rally in oil prices came primarily as the U.S. supply glut ended and disruptions from power outages in countries such as Nigeria and wildfires in Canada hindered production.

Additionally, Sterne Agee upgraded the Houston-based oil and natural gas company's stock to "buy" from "neutral" with a $47 price target.

"We have long viewed Noble as a great company. We now view NBL shares as a compelling investment, given overblown geopolitical headwinds, operational momentum and attractive valuation amid YTD (year to date) underperformance," Sterne Agee analysts said in an investor note this morning.

Separately, TheStreet Ratings rated Noble Energy as a "sell" with a score of D.

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon.

Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author. TheStreet Ratings has this to say about the recommendation:

This is driven by a few notable weaknesses, which TheStreet Ratings believes should have a greater impact than any strengths, and could make it more difficult for investors to achieve positive results compared to most of the stocks that are covered.

The company's weaknesses can be seen in multiple areas, such as its deteriorating net income, disappointing return on equity, weak operating cash flow, generally disappointing historical performance in the stock itself and feeble growth in its earnings per share.

You can view the full analysis from the report here: NBL