By midafternoon, shares had surged 13.7% to $6.80.
Trading volume of 1.4 million was more than triple its three-month daily average.
Houston-based VAALCO reported net income of $26.4 million, or 46 cents a share, in the three months to December compared to a net loss of $18.9 million, or 33 cents a share, in the year-ago quarter.
Analysts had expected net income of 34 cents a share, according to averages compiled by Thomson Reuters.
Over fiscal 2013, the crude oil and natural gas producer reported net income of 74 cents a share, 9 cents higher than estimates.
Full-year revenue of $169.28 million was slightly higher than consensus of $168.1 million. However, sales dropped 13.3% lower than a year earlier.
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TheStreet Ratings team rates VAALCO ENERGY INC as a Hold with a ratings score of C. The team has this to say about their recommendation:
"We rate VAALCO ENERGY INC (EGY) a HOLD. The primary factors that have impacted our rating are mixed -- some indicating strength, some showing weaknesses, with little evidence to justify the expectation of either a positive or negative performance for this stock relative to most other stocks. The company's strengths can be seen in multiple areas, such as its revenue growth, largely solid financial position with reasonable debt levels by most measures and expanding profit margins. However, as a counter to these strengths, we find that the company's return on equity has been disappointing."