Apple vs. Exxon: What's the better buy?

Like most investors, I look to put my money into profitable, fast-growing companies with rapidly rising stock prices. Right now, no business fits that profile better than Apple. Last quarter's earnings didn't just beat estimates, they blew them into another dimension. Investors have responded by piling into Apple's stock. The tech darling, already the largest company in the world by market cap, has added more than $100 billion to its valuation in a single month.

Apple and Exxon
Scott Mlyn | CNBC; Getty Images

Apple is now twice as valuable as the world's second-largest company by market cap, Exxon, which has posted decidedly less-exciting results in recent quarters. Dropping oil prices have cut into Exxon's revenues and its stock has struggled in the last six months. Warren Buffett, one of my investing heroes, has unloaded his entire stake in the company.

And yet, if I could only buy one stock right now to hold for the long haul, I would grab XOM over AAPL in a heartbeat.

Read MoreApple to hold event March 9, Watch likely

For all of Apple's successes, it is essentially a consumer-products company and, lately, it's become a consumer-products company with exactly one hot-selling consumer product: a phone. IPhone sales generated about 70 percent of Apple's revenues last quarter. Revenue growth from other products like iPads is flagging, and even the most optimistic projections for sales of the forthcoming smartwatch are relatively modest. That means for the foreseeable future, Apple will continue to rely on the popularity of a single consumer product for the bulk of its revenues. That's dangerous, especially in the tech world where even the most dominant players can go from hero to zero in a very short time frame.

I'm old enough to remember former tech behemoths like Digital Equipment Corporation and Sun Microsystems. Like Apple today, those companies reaped huge revenues from the hot-selling tech products of their day. And like Apple itself did at one time, they both wound up collapsing after they failed to adapt to market shifts. A few decades ago, the popularity of Microsoft's Windows operating system crushed Apple's market share. Today, its Surface tablet is proving a formidable challenger to Apple's iPad, and there is no guarantee that Microsoft or another corporation won't finally cut into the iPhone's dominance, as well.

Read MoreApple car: 5 reasons it's intriguing, 5 reasons it's nuts

A large part of Apple's appeal stems from its well-earned reputation for innovation, and many investors are betting that the company will invent new bestselling products in the near future. (Will I have to update the OS of my Apple Car every three months, too?) But Exxon has shown a surprising knack for Apple-like adaptability and innovation, too. It's not just an oil company, it's an energy company in all senses of the word, and it dominates the wider energy sector in a way that Apple could only dream of dominating its industry. Exxon is the world's largest corporate producer of natural gas. It is also a major refiner and chemical maker.

Alternative energy enthusiasts believe that technologies like wind and solar power will eventually supplant fossil fuels. Maybe they're right, but I am certain that if that happens, Exxon will be just fine. The minute those technologies start to dent its revenues, the company will do exactly what it did in the natural gas space: use its massive cash flows to expand into new opportunities. Five years ago, Exxon bought gas giant XTO Energy and it has continued to acquire other large gas concerns since then. You can bet it will conduct the same kinds of acquisitions in the renewables sector if those sources begin to provide a significant percentage of our energy needs.

Read MoreCramer: Worst yet to come for the oil patch

Exxon's diversification and smart management will bring the company through the recent oil bust stronger than ever. I strongly doubt that Apple could weather such a challenging period. Even with more than $150 billion sitting in the bank, its stock is only one subpar quarter away from a major correction. That's why, if I had to choose between the two companies, I would pick up my iPad, log into my brokerage account, and buy stock in Exxon.

Commentary by Scott Fearon, the founder and president of Crown Capital Management. He is also the author of "Dead Companies Walking: How a Hedge Fund Manager Finds Opportunity in Unexpected Places," which chronicles his 30 years of experience in the investment management industry.