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Taking the long view is never easy. Even so, buying and holding stocks for lengthy periods of time -- such as a decade or longer -- is the only strategy proven to produce substantial gains on a consistent basis. Armed with this insight, our Foolish contributors offer five stock picks below that might be worth holding onto for the long-haul.  

A long term investment loaded with... trash?

Tyler Crowe: Sometimes it's hard to conceptualize how fast things change in a decade. Some things that seem to be almost ubiquitous in our lives today didn't even exist just over a decade ago. As much as some aspects of our lives have moved at the speed of light, there are some things that have remained constant. Not surprisingly, those sorts of things -- the slow to progress industries that serve a basic need -- are some of the best places to invest for a decade or more. One need that hasn't changed over decades is basic sanitation like trash removal. That makes trash handler Waste Management (WM 0.94%) one of the best investments for those with a decade long time horizon. 

Waste Management has two critical qualities that you want in a long term investment: A solid business model that is immune to economic cycles, and a management team that nurtures those advantages through effective operations and capital allocation. For Waste Management, it has immense competitive advantages that prevent others from getting involved in its business, and the necessity of trash removal and proper disposal gives it some pricing power to keep profits coming in the door. Waste Management also has the benefit of a management team that has always kept an eye on operational costs and smart capital allocation that has led to annual returns on equity greater than 10% for well over a decade. 

With little chances of the waste industry changing much in the next decade, then it's very likely that Waste Management will be a solid investment to hold for a decade and maybe more. 

Short term pain, long term gain

Tim Green: A long track record doesn't guarantee that a company will succeed in the future, and that's doubly true in the world of technology. Buying and holding a tech stock for a decade is inherently a risky proposition, simply because it's impossible to predict how the industry will change. But I think one exception is International Business Machines (IBM 2.54%).

IBM has been around for over a century. The company originally made a name for itself selling and leasing mechanical tabulating machines, eventually moving into computers. Its hulking mainframe systems, first launched more than 50 years ago, are still used in a variety of industries today. The company has made a habit of dramatically transforming itself over the decades, a necessity for any tech company that aims to stand the test of time.

IBM is currently going through another transformation, this time putting its focus on cloud and cognitive computing. The upheaval that this is causing, with resources being shifted away from legacy businesses, has contributed to a long string of disappointing results. Revenue has been slumping for four years, and profits are also moving in the wrong direction.

But IBM's growth businesses are growing fast. Cloud computing now generates $10.8 billion of revenue annually, with half of that total coming from cloud delivered as a service. Analytics is an $18 billion business that grew by 16% in 2015, and Watson, the company's cognitive computing system, is being used for a wide variety of applications. IBM's transformation has been painful for investors, but I believe that those willing to hold the stock for the next decade will like the results.

Quenching your thirst for income and growth

Dan Caplinger: PepsiCo (PEP 1.48%) has been a solid performer for investors for decades, and it has plenty of prospects to continue delivering strong returns to shareholders in the years to come. The company has a well-diversified portfolio of products that combines both its namesake cola and other beverages with a variety of snack foods under the Frito-Lay division. This combination has allowed PepsiCo to avoid some of the difficulties that its more concentrated rivals have faced, given the rising tide of legislation and taxation on sugary carbonated beverages in a public-health battle to fight high obesity rates. In addition, PepsiCo was early to realize that innovative new snack products could ride on the popular trend toward healthier food, and that insight has prevented the company from getting left behind.

One of PepsiCo's strongest traits is its dividend. The stock currently has a 2.8% yield, and it has a history of raising its quarterly payout each and every year going back for 44 years, making PepsiCo a member of the elite Dividend Aristocrat list. Just last month, PepsiCo gave shareholders a healthy 7% boost in its dividend payments. When you look at opportunities for current income and impressive future growth, PepsiCo stands out as a stock that can give you the best of both worlds.

Exelixis is starting to get on its feet

George Budwell: I think Exelixis (EXEL -0.67%), a biopharma developing small molecule drugs for the treatment of cancer, is a compelling long-term buy due to the second FDA approval for its tyrosine kinase inhibitor, cabozantinib (Brand names: Cabometyx & Cometriq), in advanced kidney cancer. In a nutshell, Exelixis now seems to have a viable franchise-level drug on its hands that could fuel its growth for the long-haul. 

There are a lot of moving parts to Exelixis' value proposition at the moment, though, such as the potential impact of the relatively recent approval of Bristol-Myers Squibb's Opdivo for this exact same indication. The good news is that cabozantinib appears to have a slight competitive edge over Opdivo, given that it showed a significant improvement in progression-free survival and overall survival, when pitted against the current standard of care in its late-stage trial. Opdivo, by contrast, garnered its approval based solely on its ability to improve the duration of overall survival, perhaps opening the door for cabozantinib to grab the lion's share of the market. 

Looking ahead, Exelixis expects to release top-line data from cabozantinib's pivotal trial in advanced liver cancer next year. Truth be told, I think the drug's chances of meeting its primary endpoint of improving overall survival, compared to placebo, in advanced liver cancer patients that have already been treated with the kinase inhibitor sorafenib are probably slim to none. Liver cancer is, after all, notoriously difficult to treat.

Despite cabozantinib's dim prospects in liver cancer, Exelixis should still see a marked improvement in its balance sheet over the next few years because of the drug's recent approval in advanced kidney cancer -- giving the biotech the financial resources necessary to build out a broader product portfolio down the road. 

Visualize these market-beating returns

Steve Symington: NVIDIA Corporation (NVDA 1.44%) stock is up 60% so far in 2016 as of this writing, but I think it has plenty of room run higher yet.

The graphics processing unit (GPU) specialist shipped nearly 79% of the world's dedicated graphics cards in the fourth quarter of 2015. And though we'll need to wait until its next quarterly report in August to see exactly how well NVIDIA's newest GeForce GTX series cards have sold, fellow Fool Ashraf Eassa pointed out last week it appears demand for the high-end GTX 1080 -- which reviewers have praised as the fasted single-processor graphics card on the market today -- has continuously outstripped supply since its launch.

During NVIDIA's most recent quarterly call in May, NVIDIA CEO Jen-Hsun Huang also noted a sharp increase in customer engagement for the company's deep learning solutions, which capitalize on the GPU's superior computing power to better learn artificial intelligence algorithms that will only become more important as our technology-centric world continues to progress. NVIDIA's technology is particularly well-suited to solving a plethora of difficult problems from self-driving automobile and robotics navigation, to data visualization, image and speech recognition, gaming, natural language processing, and life sciences, all of which which should continue serving to drive demand for its GPUs in the coming years. 

Meanwhile, NVIDIA has a history of aggressively returning capital to shareholders without sacrificing R&D. Last fiscal year, NVIDIA spent roughly $1.33 billion on R&D, consistent with its prior year and around 40% higher than that of struggling competitor AMD (AMD -0.18%). But the company has returned over $3.5 billion to investors since instituting its capital return program at the end of fiscal 2013, and plans to return a total of $1 billion through dividends and repurchases when all is said and done in fiscal 2017. For investors willing to buy now and watch as NVIDIA's GPU technology becomes ever more pervasive, I think the stock will be significantly higher a decade from now.