Investors can always find promising long-term holding options among mid-cap companies that operate in large and growing markets.

Smartsheet (NYSE:SMAR) and Upwork (NASDAQ:UPWK) both fit that description, and both are experiencing strong tailwinds. Smartsheet is a leader in workflow management software, while Upwork is tapping into the secular trend of remote work. Here's why their stocks are good bets to double in value over the next decade.

A remote worker sitting at a desk with three computers.

Image source: Getty Images.

Smartsheet

Smartsheet was founded in 2005 to provide a single, easy-to-use application that helps business teams to execute projects more efficiently. Its platform is helpful for a wide range of business needs, such as launching brands, compliance reporting, budgeting, patent applications, and sales operations. 

The company generates revenue from subscriptions and its top line has grown rapidly, from $40.7 million in fiscal 2016 to $385 million in fiscal 2021. There are good reasons to believe it get much bigger over the next decade.

Smartsheet is already used by some of the biggest companies in the world, including Apple, Procter & Gamble, and American Express, just to name a few. Its client roster includes 80% of the Fortune 500. Smartsheet entered the year with 1.2 million paying users and is currently working to convert more of its 6.8 million existing free users to paid users. 

What's more, management sees an opportunity to take market share from traditional project portfolio management providers. To help it accomplish that goal, Smartsheet recently acquired Brandfolder. The combination of Brandfolder's digital asset management capabilities with Smartsheet's work management platform gives the company a tremendous opportunity to meet a need in a niche where there is little competition right now.  

Naturally, given the advantages Smartsheet possesses and its opportunities for growth, the stock looks expensive. Its market cap is currently $9.3 billion. Relative to its revenues of $457 million, that gives it a fairly high price-to-sales ratio of about 20, but Smartsheet can grow into that valuation. It generates a high adjusted gross margin of more than 80%, and management expects revenue for its fiscal 2022 (which began on Feb. 1) to increase by 37% to 38%. More growth and better leverage of operating expenses should pave the way for a profitable business down the road.

With that kind of momentum, investors who buy the stock now could easily double their money by 2030.

Upwork

The pandemic has compelled many businesses to rethink how they scout talent. Upwork connects millions of businesses with freelancers and independent workers from around the world. It serves companies of all sizes, from about half of the Fortune 500 all the way down to small start-ups. 

Upwork has experienced strong growth during the pandemic, as more businesses relied on remote workers to stay productive. But it was already a fast-growing business before 2020, with revenue growing at a compound annual rate of 25% from 2016 through 2019. 

Even as more people have returned to their workplaces this year, Upwork has accelerated its revenue growth, posting an increase of 39% year over year through the first half of 2021. This momentum reflects the changing perspective of employers on the value of remote workers. For example, a recent PwC survey found that only 21% of employers think their employees need to be in the office five days a week. 

Upwork is also benefiting from a network effect advantage. As more freelancers join the platform, more businesses turn to it to fill critical gaps in their workforce. The opportunity is massive, with Gartner estimating the value of the global remote work market at over $1 trillion. 

Upwork is already emerging as a leading brand in this burgeoning market. Most importantly, it's building trust with its clients, including the people joining its marketplace to find gigs. This mid-cap stock has already returned 221% over the last few years and could repeat that performance for investors who patiently hold it through 2030. 

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.