Investing is easy, right? Just buy low and sell high, and there's your fortune.

That's how the stock market would work in a perfect world, where there is no friction and you can assume that every cow is a perfect sphere. In the real world, even the best investments often hang around at uncomfortable price levels for a long time. The payoff is coming in the long run, but Wall Street is not a get-rich-quick scheme.

Truly successful investors are looking for high-quality companies that should survive and thrive for many years to come, and they have saintly patience with the bumps in the road. Time and patience combined will build wealth in the stock market.

On that note, some of my own investments look cheap today. Some of them are fairly new additions to my portfolio, while others have been with me for years. Either way, I have no intention of selling them any time soon. That would just lock in poor returns forever and leave me watching from the sidelines if and when my investment thesis finally gains traction.

Here are three of the cheapest stocks I own, and why I'm more likely to increase these investments than to close out these humble positions.

1. IBM

I picked up a few shares of International Business Machines (NYSE:IBM) in 2015. The original position has lost 13% of its value in six years. If you include the dividends I reinvested over the same period, I have a positive total return of 15% so far. Meanwhile, the assets I invested in Big Blue missed out on some phenomenal gains in the broader stock market.

Chart showing steady trend in IBM's price percent change and total return, and upward trend in S&P 500.

IBM data by YCharts

I'll admit that I expected this investment to start lifting its weight quite a bit earlier. IBM has been shedding low-margin operations for a full decade now, focusing wholeheartedly on more lucrative and promising markets such as cloud computing, artificial intelligence, and the nuts and bolts of blockchain technologies. The tipping point where IBM's patient and painful transformation should start producing generous sales growth and free-flowing cash generation always seems to lurk around the next corner.

Many investors are losing their patience with IBM's slow progress toward a game-changing payoff. The stock currently trades at penny-pinching valuation ratios such as 11.7 times forward earnings and 13 times trailing free cash flows.

That's OK. IBM looks like a solid buy at these bargain-bin prices, and those reinvested dividends are only buying more additional stock per quarter while the discount lasts.

The IBM you see today looks a lot like open-source software specialist Red Hat, with a much larger bank account. Since IBM bought that business two years ago, Red Hat has become the centerpiece of the larger company's software operations. For example, in the recently reported second quarter of 2021, Red Hat revenues rose 20% year over year while IBM's total sales increased at a slower pace of 3%. So, the Red Hat takeover continues.

I'm content to sit on my growing pile of IBM shares and wait for the Red Hat-based strategy shift to take full effect. If artificial intelligence and cloud computing are the future, IBM is well-positioned to deliver fantastic long-term growth in those markets.

2. Roku

Streaming media technologist Roku (NASDAQ:ROKU) isn't cheap in any traditional sense of that word. The stock trades at 225 times forward earnings and 250 times free cash flows. The stock has more than doubled over the last 52 weeks, and my own Roku holdings have quadrupled in value since the coronavirus-stricken spring of 2020.

All that being said, two qualities of Roku's stock make me think of it as a cheap investment right now:

  • Share prices have moved sideways since last December. If you opened your position the week before Christmas, you would be looking at a paper loss in your Roku investment.
  • That $46 billion market cap may look beefy next to Roku's modest earnings and revenues, but it's nothing next to the trillion-dollar behemoth I expect the company to become in the long run.

The whole world is moving its entertainment content away from cable TV and movie theaters and into media-streaming hardware in the living room. Roku was an early leader in set-top boxes for streaming media services but has already graduated to a global provider of user-friendly software platforms instead. Of course, it isn't the only game in town, but there is room for several big winners in this massive market.

Come back in five years or a decade, and you'll find Roku's current market cap to be quaintly adorable. This company has a lot of growing up to do, and so does the stock.

A ray of sunlight hits a treasure chest in an otherwise dark cave.

Image source: Getty Images.

3. Fiverr

Like Roku, freelance services marketplace Fiverr International (NYSE:FVRR) offers a gigantic target market and a modest market cap. In this particular case, I'm nursing a negative return of 25% on a position I opened in January. Some investors fear that Fiverr's moment in the sun will pass as soon as we get a handle on the COVID-19 pandemic, driving stock prices nearly 50% below the all-time highs of February.

I can't entirely agree with that notion. Instead, I would argue that freelance services are becoming a normal part of the labor market. The so-called gig economy is here to stay. Fiverr connects freelancers with people and companies who need their services better than anyone else. Fiverr's annual sales of $252 million amount to a rounding error in a worldwide market worth more than $100 billion per year.

That's why I'm happy to sit on my hands, not letting those twitchy trigger fingers hit the "sell" button on my Fiverr shares. If anything, I might pick up a few more at these bargain-bin prices. Yes, I know that Fiverr's valuation ratios are even higher than Roku's. Nevertheless, I still think it's one of the cheapest stocks in my portfolio.

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.