By Kate Gibson

As crude on Friday hit a high for the year above $74 a barrel, energy shares rallied, fueling the broader U.S. stock market towards weekly gains. But if oil's price gains continue, what has been viewed as a bullish signal could easily turn bearish for U.S. stock market investors.

Positive U.S. and European economic data, along with weakness in the dollar, helped in supporting oil's surge, with the front-month futures contract lately up $1.13 at $74.04 a barrel, after hitting $74.72 a barrel, its highest level so far this year. .

On Wall Street, energy shares fronted the broad market's advance, with shares including Cameron International Corp. (CAM), Smith International Inc. (SII) and Massey Energy Co. (MEE) all gaining more than 4%.

The Dow Jones Industrial Average (DJI) added 135.05 points to 9,485.10, while the S&P 500 Index (SPX) climbed 15.97 points to 1,023.34. The Nasdaq Composite Index (RIXF) rose 25.70 points to 2,014.92.

While crude's climb on Friday had it rallying to its highest point yet for the year, a barrel of oil remains roughly half of where it stood at its height last summer, when crude-oil futures on July 11 hit an intraday high of $146.65, with the Dow industrials shed 129 points that day.