Want to supercharge your investment portfolio? Bet on rapidly growing companies that serve established markets in exciting new ways. Virgin Galactic Holdings (NYSE:SPCE) and Roblox (NYSE:RBLX) fit the bill as they reimagine the tourism and video gaming industries, respectively.

Let's explore the reasons why these growth stocks look poised for bull runs. 

1. Virgin Galactic

On July 11, Virgin Galactic completed a historic feat by sending its founder, Sir Richard Branson, to lower space, beating out rivals Blue Origin and SpaceX, both of which are attempting similar missions. The company is now closer than ever to commercial operation, giving investors an unprecedented opportunity to bet on the burgeoning space tourism industry.

The stock's recent sell-off looks like a temporary blip on its long-term trajectory. 

Bullseye on a dollar symbol

Image source: Getty Images.

According to analysts at UBS, the space industry could grow from $400 billion to $805 billion by 2030, with tourism and hypersonic point-to-point travel representing markets of $3 billion and $20 billion, respectively. Virgin Galactic's successful test flight is a proof of concept for both of these opportunities because they involve transporting humans into near space.

Despite the good news, shares have fallen 34% since the flight because Virgin Galactic also issued $500 worth of additional stock after the announcement. The sell-off might be overdone because, although capital raises dilute existing shareholders, they also give the company a much-needed runway to scale up its operations -- which will involve "building a lot of spaceships," according to Branson. 

Virgin Galactic reported cash and equivalents of $617 million in the first quarter compared to an operating loss of $81 million in the period. Management has been tight-lipped about when it plans to transport paying customers to space. But the company boasts 600 "future astronaut" reservations, suggesting it could experience healthy demand when its space tourism service becomes available. 

2. Roblox 

Tween-focused entertainment giant Roblox is revolutionizing the video game industry with its unique business model. Instead of developing and marketing game software, Roblox operates a game-creation engine that allows users to create content. User growth is decelerating from levels achieved during the coronavirus pandemic. But Roblox still boasts a massive addressable market as it expands the possibilities of its platform.

First-quarter revenue soared 140% to $387 million year over year, which is an acceleration from the prior quarter when revenue grew 110% against the prior-year period. Growth in daily active users (DAUs) shows the opposite trend -- deaccelerating to a 79% increase (42.1 million users), from 94% in the previous quarter. 

Management's challenge will be to maintain Roblox's user growth as coronavirus tailwinds fade while also better monetizing existing users. To help pull this off, the company is expanding outside video games. 

In July, Roblox announced a partnership with Sony to build music experiences around Sony artists within its platform. The company is also betting on video entertainment, with a virtual launch party for Warner Bros. film In the Heights, along with mini-games based on Netflix's show Stranger Things. These initiatives may also help Roblox appeal to older users (above age 13), which represent roughly 49% of its user base. 

What is your risk tolerance?

Virgin Galactic and Roblox offer investors an excellent opportunity for long-term growth as they reinvent their respective industries. But Roblox is probably the safer bet because of its more established business, while Virgin Galactic is ideal for those willing to tolerate more uncertainty to get in on the ground floor of the space tourism industry. 

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.