The broad-based S&P 500 (SNPINDEX:^GSPC) has been on an absolute tear in recent years. Over the trailing five-year period, through March 10, 2018, the S&P 500 was up 79%. Mind you, the stock market historically averages a return of 7% per year, inclusive of dividend reinvestment and when adjusted for inflation. Over the past five years, it's practically doubled its historic average return.

Can any other asset classes top the stock market's returns over the next decade?

Yet investors are often left to wonder if they're truly taking the smartest investment path forward. In other words, is investing in a broad basket of stocks via the S&P 500 the best way to put your money to work over, say, the next 10 years, or are other assets, such as bitcoin, marijuana stocks, or gold, a considerably smarter play over the next decade?

Truth be told, all four investment classes -- bitcoin, marijuana stocks, gold, and the S&P 500 -- offer pros and cons. Let's have a look at what each asset offers investors, and then decide once and for all whether they have a genuine shot to outperform the stock market over the next 10 years.

A physical gold bitcoin, up close.

Image source: Getty Images.

Bitcoin

Cryptocurrency bitcoin is the darling of the retail investor. This relatively new peer-to-peer payment method has exploded since the turn of the decade, and in just eight years we've seen the value of each bitcoin token catapult from $0.003 to nearly $20,000 at one point. Such astronomical returns are extremely rare -- but are they sustainable, and can bitcoin rise even more in the future? Let's take a closer look.

Bitcoin's pros:

  • Working in bitcoin's favor is that retail investors predominantly control the show. Since most bitcoin trading occurs on decentralized cryptocurrency exchanges, and institutional investors usually want nothing to do with these decentralized exchanges, bitcoin is driven by the emotions of retail investors, rather than by fundamental reason. Emotions can be a powerful tool in pushing virtual currency valuations higher.
  • Also, there aren't many ways for skeptics to bet against bitcoin. Even though the CME Group and CBOE Global Markets have both been offering bitcoin futures contracts since December, which allows investors to finally bet against bitcoin, each contract equates to a one- or five-bitcoin bet. In effect, the investor may have to put up around $10,000 to $50,000 to bet on a downside move in bitcoin, which could price a lot of investors out of making this bet. There's considerably more incentive to push cryptocurrency prices higher than lower for this reason.
  • Bitcoin is also responsible for pushing blockchain technology into the spotlight. Blockchain is the digital, distributed, and decentralized ledger underlying most cryptocurrencies that's responsible for logging all transactions without the need for a bank. Its evolution could wind up reducing transaction fees on blockchain networks and significantly speeding up transaction validation and settlement times.
A physical gold bitcoin in a mouse trap.

Image source: Getty Images.

Now for the cons:

  • There's little in the way of fundamental backing behind bitcoin, with sheer emotion powering this train. Bitcoin's focus is on signing up as many merchants as possible to accept its token, which is a difficult metric to measure and quantify into an actual monetary value.
  • Regulators are beginning to clamp down on bitcoin, which has benefited from loose government regulations up to this point. Now, bitcoin is banned in a half-dozen countries worldwide and is facing more rigorous regulation in South Korea, China, and the United States. Though regulation can help validate bitcoin as a legitimate asset, it takes away perceived aspects, such as the anonymity that made it initially so attractive to investors.
  • Lastly, blockchain has come a long way since bitcoin made its debut in 2009, and the fact is that bitcoin's network is rather slow compared with many of its peers. With an average transaction processing time that can eclipse an hour, bitcoin may find that its days as a medium of exchange are numbered.
A person holding cannabis leaves in their cupped hands.

Image source: Getty Images.

Marijuana stocks

Within the stock market, no asset class has been hotter than pot stocks over the past couple of years. Many of the largest marijuana stocks by market cap have doubled or tripled in value over the past year, and are up by more than 1,000% over the trailing two-year period. The big question is: Can this industry keep budding?

The pros of marijuana stocks:

  • The primary lure of marijuana stocks is their impressive sales growth potential. Leading cannabis research firm ArcView, in partnership with BDS Analytics, suggests that North American legal weed sales could grow by 28% between 2018 and 2021, leading to almost $25 billion in annual legal cannabis sales. Mind you, this estimate jumped by $3 billion from the previous year, and still takes into account the harsh stance the U.S. bears toward pot.
  • The public is very much in favor of seeing marijuana legalized, at least in the United States. All major marijuana polls demonstrate strong favorability toward legalization.
  • Canada appears to be on the verge of legalizing recreational cannabis by this summer. With a two-year tax-sharing agreement in place with most provinces, and the required votes looking to be in place in parliament, Canada could become the first developed country in the world to legalize adult-use pot. Recreational marijuana's legalization in Canada would bring in an estimated $5 billion or more a year in sales.
  • We've even begun to see a select few pot stocks generate quarterly and annual profits. Even though these have been generally marginal on a per-share basis, the business model is looking sustainable in the early going.
A judge's gavel next to dried cannabis buds.

Image source: Getty Images.

Bluntly, the cons of pot stocks:

  • Regulation is a serious concern for pot stock investors. Though we've seen a flurry of countries legalizing access to medical cannabis, recreational weed is still illegal in every country, except Uruguay. Within the U.S., Attorney General Jeff Sessions is doing everything imaginable to halt the expansion of weed at the state level. Mind you, without interference from Sessions and the federal government, the U.S. could be the largest cannabis market in the world in terms of sales.
  • Dilution is a serious investor concern. Since marijuana companies usually lack access to basic banking services, they have little access to capital beyond their operating cash flow, which is often minimally positive at best. Many, such as Aurora Cannabis (NYSE:ACB), have turned to bought-deal offerings, which involves selling stock, debentures, options, or warrants, to raise capital for capacity expansion. In doing so, Aurora Cannabis has ballooned its outstanding share count by more than 2,900% in four years.
  • Oversupply is another major concern. With Canada on the verge of legalization, growers have been expanding their increasing capacity as quickly as their wallets will allow. The aforementioned Aurora Cannabis expects to produce 240,000 to 270,000 kilograms per year. In fact, the top five producers might offer enough production by themselves to satiate all of Canada's demand. The issue is that there are 91 licensed producers, not just a small handful, meaning a glut of cannabis could decimate margins and profitability. 
Gold bars lying next to each other.

Image source: Getty Images.

Gold

Another popular investment alternative to the stock market is gold, which has been used as a form of currency for centuries and is often a safe haven that investors flock to when there's even the slightest hint of fear apparent in the stock market. Back in the first quarter of 2016, the last time the stock market corrected before our most recent correction in February 2018, gold rattled off its best single-quarter performance in 30 years. Can this lustrous yellow metal outperform the stock market over the long run?

The pros of gold:

  • When it comes to stores of value, gold is king. When the U.S. dollar is dropping, or inflation is rising, investors regularly flock to gold, which holds its value thanks to both its perception as the go-to store of value and given its relative supply scarcity -- the gold that's on our planet right now, either buried in the ground or mined, is all there will ever be.
  • Gold has the ability to perform well in either an expanding or contracting economy. As noted, it tends to be an excellent place for investors to hide when fear enters the marketplace. Likewise, supply and demand still play a critical role in determining the future price of gold. An expanding global economy is likely to see an uptick in gold demand for industrial and dental uses, as well as by investors looking to diversify their investment portfolios.
  • Gold could continue to benefit from a Federal Reserve that's walking on eggshells when it comes to federal funds target rate increases. Following 10 years of low interest rates and subpar yields on interest-bearing assets, gold continues to be an attractive alternative.
Molten metal being poured out of a foundry.

Image source: Getty Images.

The cons that could cause a meltdown:

  • On the other hand, gold tends to be interest rate sensitive since it offers no yield, meaning the higher yields go on interest-bearing assets, the more likely investors are to overlook or abandon gold in favor of more guaranteed returns from bonds and bank CDs. The Fed is currently in a monetary tightening period, which could progressively put pressure on gold as interest rates move higher.
  • Gold is a commodity and as such has a tendency to move in step with other commodities. Historically, gold has a tendency to get into extended bull markets, followed by extended bear markets. Since 2011, gold is down by more than 25% from its peak, and since 1800, according to the Wells Fargo Investment Institute, the average bear market for commodities lasted almost 20 years. History would therefore not favor a quick rebound in gold prices. 
  • Finally, even if inflation is often viewed as a positive for gold, it often creates a knee-jerk reaction with interest rates. Inflation is usually apparent in rapidly growing economies, which tends to coerce central banks to raise interest rates to slow inflation. Thus, many of the biggest catalysts for gold tend to be short-lived, as they're often countered by a negative reaction.
An investor cheering in front of a rising stock chart.

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The stock market (S&P 500)

And then, of course, we have the stock market, which we'll represent by the broad-based S&P 500. Should you consider putting your money to work in this basket of around 500 stocks over the next decade? Let's have a look.

The pros of investing in a basket of stocks:

  • The clearest benefit of investing in stocks is the ability to examine the fundamental factors that drive valuations. Whereas emotions do play a role with all of the asset classes mentioned here, they can be minimized with stocks, as there are balance sheets, financial statements, and metrics galore that investors can be pore over to determine what they'd consider a fair valuation for a company or group of companies.
  • A basket of stocks like the S&P 500 pays you to invest. The average yield on the S&P 500 has been hovering around 2% for years now. This yield is a result of having hundreds of companies within the S&P 500 pay a dividend as a result of their time-tested and highly profitable business models. Dividends are a great way to somewhat hedge your downside during inevitable stock market corrections, as well as build wealth through reinvestment.
  • History suggests you're smart to buy stocks. As noted, the stock market has gained 7% over the long run, inclusive of dividend reinvestment and when adjusted for inflation. That would imply a rough doubling in your investable assets about once every decade, assuming the averages were perfectly adhered to.
A worried man looking at a plunging stock chart on his computer screen.

Image source: Getty Images.

The cons of investing in the S&P 500:

  • Investors should understand that stock market corrections are inevitable, and that no asset, not even the stock market, goes up forever. Since 1950, according to data from Yardeni Research, the S&P 500 has had 36 stock market corrections that, when rounded to the nearest whole number, totaled at least 10%, the minimum amount to quality as a "stock market correction." That's roughly one correction every two years.
  • Emotional investors still have the capacity to overshoot to the upside or downside. Even with access to copious amounts of financial statements and balance sheet data, fear can get the better of short-term traders from time to time and lead to violent swings in the stock market. What happened in February, with the Dow tumbling by 1,175 points, 1,033 points, and 666 points, just a few days apart from one another, is a perfect example of this process in action.
A smiling woman reading the financial section of a newspaper.

Image source: Getty Images.

Your best bet for the long term is...

After this review, it should be pretty evident that the best place to park your money for the most consistent long-term returns is the stock market/S&P 500.

Think about it this way: The stock market gives you access to time-tested business models that tend to increase in value over time, a healthy dividend that you can reinvest, exposure to the U.S. and global economy, and the ability to intricately examine fundamental data that can help in valuing businesses or groups of companies. Plus, each and every stock market correction over the past 68 years, not counting our current one, has been erased by a bull market rally, often within weeks or months. History shows that stocks spend almost three times as many days rallying than they do in correction.

You simply can't get this full package with any of the other asset classes mentioned here. Bitcoin lacks a time-tested business model and fundamental backing, and it pays no dividend. Meanwhile, marijuana is illegal in nearly every country, putting the business model in jeopardy, and since most pot stocks are losing money, dividends aren't a possibility. Even gold, which has a rich history, lacks a dividend and has historically underperformed the stock market over the long run.

Sorry, folks, but despite their near-term buzz, bitcoin, marijuana stocks, and gold are likely to take a back seat to the stock market over the next decade.

Sean Williams has no position in any of the stocks or cryptocurrencies mentioned. The Motley Fool owns shares of and recommends CME Group. The Motley Fool recommends Cboe Global Markets, but has no position in any cryptocurrencies mentioned. The Motley Fool has a disclosure policy.