Analysts don't see this boom going bust yet, even if the oil service rally does moderate.
Kurt Hallead, managing director and co-head of global energy research at RBC Capital Markets, said that oil field services companies should see 18 more months of strong gains.
Hallead thinks Halliburton, which is trading at $65 today, could rise by about 8 percent to $70 over the next 12 months. Baker Hughes could climb by about 4.2 percent, to $74 a share, while Schlumberger could rise by nearly 10 percent to $115. "The outlook is very positive," he said.
A classic rule of thumb for investors is to leave a little money on the table if you've had big gains, rather than stick around for the last legs of a rally. Another way of saying it is, don't get greedy. Another 4 percent to 8 percent gain may not seem like much to hang around for, especially for stocks tied to a sector that can always be prey to macroeconomic shocks.
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For a current bull like Hallead, there is one main reason to stay invested in these stocks: strong energy prices. These companies do well when oil and gas prices are stable or climbing.
"The revenue stream of an oil field services company is equal to the cash flow stream of an oil company, and that cash flow stream ties back to crude oil and natural gas prices," he explained.
Since January 2013, crude oil prices have mostly been in the $90 to $100 range, while natural gas prices have climbed by 127 percent from hitting rock bottom in April 2012.
Hallead points out that most investors think prices will stay strong. A recent RBC poll found that 75 percent of investors think crude oil prices will remain stable at around $100, while an equal number think gas prices will hover around the $4.50 (per million British thermal units) it's at today.