ConocoPhillips (NYSE: COP) made a splash last week with plans to spin-off its refining operations as a way of making its share price rise more in tandem with its fast-growing production business. The split, Conoco execs figure, will give its production company the respect it deserves on Wall Street.

But does this development really make ConocoPhillips the best of domestic big oil to buy in today's market? YCharts Pro pegs ExxonMobil (NYSE: XOM) and Chevron (NYSE: CVX) as well as Conoco, as having excellent fundamentals, although it marks all as slightly overvalued.

Conoco, the third-largest of the trio, has been preparing for the big break-up since late 2009. That's when it started selling off billions of dollars in assets that didn't fit neatly into either core production or refining operations. Its share price rose as assets fell off, eventually making Conoco investors happier than even Exxon or Chevron shareholders. Not that anyone in these giants has had much reason to complain lately.

ConocoPhillips Price Stock Chart by YCharts

But Conoco is tired of getting dissed by Wall Street. Despite rapid earnings and revenue growth due to high oil prices, shares of Conoco and other integrated oil companies trade at lower valuations than discount stores. Conoco's is the lowest, a particular annoyance for the company since its production company is growing faster than Exxon's or Chevron's.

ConocoPhillips P/E Ratio Stock Chart by YCharts

The split will throw Conoco's production company in with the independents, where valuations of 20 and 30 times earnings are nothing unusual. There, investors pay up for the possibility of big gains. They also tend to endure bigger losses. The orange line, (IEO), represents an iShares ETF that tracks independent oil companies. The blue line, (IYE), is the iShares ETF that includes the big integrated giants.

iShares Dow Jones U.S. Oil & Gas Exploration & Production Index Fund Price Stock Chart by YCharts

Conoco shareholders also will get shares in a new Conoco refining company, where it will compete with sector favorites like Hess (NYSE: HES) and Murphy Oil (NYSE: MUR). Here, share prices often are subject to the ups and downs of commodity prices, with higher oil prices often squeezing profit margins. Here's a look at how a couple of the giants have traded compared to two big refiners. The jumpier lines across the bottom are the refiners.

Valero Energy Corporation Price Stock Chart by YCharts

In other words, with the split, Conoco investors will trade their somewhat steady shares of big oil for two more volatile companies. There's nothing wrong with that. Conoco's dividend strategy, which the company promises to protect in the reorganization, is a very nice counterbalance to volatility. It's yielding about 3.55% now, which is a heck of a lot more than anything buyable for value investors in either the independent or refinery sectors.

Conoco's announcement led to speculation that Exxon and Chevron would follow its lead and split their operations, too. But as Steve Gelsi discussed in a MarketWatch piece last week, it's not likely.

Both Exxon and Chevron get very high marks from YCharts Pro as they are today. Exxon is still a good pick for a value investor, with a price that the charts put at only mildly overvalued and Exxon's dividend marches pretty predictably upward.

Conoco's move likely will raise its valuations, although the $100 billion market cap of its new production company makes it unlikely to get to the really high valuations of the growth stocks in the sector. Still, Conoco shares aren't prohibitively expensive now, and they offer an easy way into two oil sectors at a time when demand for the stuff keeps increasing.

But if you do buy Conoco, just remember you'll soon be leaving the relative protection of big oil's diversity. It's not a bad time to pick up Exxon either.

Dee Gill is an editor for the YCharts Pro Investor Service which includes professional stock charts, stock ratings and portfolio strategies.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.