After some big sell-offs last year, Roblox (RBLX 1.35%) and DraftKings (DKNG 4.96%) have seen strong rebound momentum in 2023. Year to date, the stocks are up 37% and 123%, respectively. On the other hand, Roblox still trades down 71% from its high, and DraftKings remains off 65% from its valuation peak.

Which of these growth stocks is the better buy right now? Read on to see why two Fool.com contributors have differing opinions on which stock would wind up being a better performer for your portfolio. 

DraftKings is demonstrating explosive growth

Parkev Tatevosian: DraftKings could be an excellent growth stock for investors with a high risk tolerance. While macroeconomic headwinds have slowed growth for many businesses in the market this year, DraftKings' top-line growth has remained robust. That's mainly because DraftKings' expansion in line with approvals it has received to enter new markets. 

As a gaming company, DraftKings must gain approval to operate in each state. So far, it has done an excellent job. DraftKings is now live with its mobile sports book in 21 states, representing 44% of the U.S. population.

The customer response has shown there is strong demand for mobile gaming. Indeed, DraftKings' revenue has exploded from $192 million to $2.2 billion between 2017 and 2022. 

Still, the company is losing large sums on the bottom line. Expanding to new states is expensive. It requires legal maneuvering, customer acquisition costs, and technical expertise. In the same years mentioned, DraftKings' operating losses have worsened from $73 million to $1.5 billion.

So why invest in DraftKings stock? Because the house always wins. Gaming is a lucrative business, and mobile gaming is poised to be even more profitable than brick-and-mortar casinos. Mobile operators don't need to invest in expensive buildings, hotels, and a large staff to maintain the properties. It's reasonable to expect DraftKings could eventually generate healthy profits once all the investment in growth is finished. 

That said, it's not a certainty that DraftKings will keep gaining approval to enter new states, and at its current scale, it may not be enough to generate profitability on the bottom line. That's why DraftKings might be an excellent opportunity, but only for investors with a high risk tolerance. 

Roblox could turn into a massive long-term winner

Keith Noonan: With such tech giants as Meta Platforms and Apple making big bets on virtual reality, augmented reality, and metaverse projects, it's clear that some of the biggest, most powerful players in the tech space believe that virtual worlds present a potentially massive growth opportunity. In many respects, Roblox is already ahead of the curve when it comes to building thriving digital spaces.

Roblox closed out its first quarter with 66.1 million daily active users and 14.5 billion total engagement hours. Both of these figures came in at record levels and were up 22% year over year and 23% year over year, respectively.

Somewhere down the line, CEO Dave Baszucki thinks that the platform will be able to reach 1 billion daily active users. No doubt about it, that's an incredibly ambitious target -- but there are good reasons to think that Roblox will continue to deliver impressive growth. 

Rather than just being a single game, Roblox is actually a hub that houses thousands of different experiences. Even better, users can actually create games and experiences for the platform and earn money for their creations. The total cash paid to creators on the Roblox platform rose 24% year over year in Q1 to reach $182 million. Thanks to this incentive structure, new content is being added to Roblox all the time, and creators are also encouraged to grow and improve the content they've made that has resonated with other users. 

Last quarter, Roblox's bookings rose 23% compared to the prior-year period to reach $773.8 million. The company is serving up impressive results and has already shown it has staying power -- and it could be laying the foundations for a much bigger growth story. 

To be clear, I actually think there's a lot to like about DraftKings stock as well. The online betting specialist is posting explosive growth, and I wouldn't be surprised if it's able to continue leveraging its strong industry positioning and deliver big returns for long-term shareholders. But regulatory uncertainty on the horizon comes with risks that make me prefer Roblox. 

So which stock is the better buy?

DraftKings and Roblox are both leaders in service categories that have massive expansion potential. If you're only interested in owning one of these stocks, it makes sense to weigh each company's strengths and the growth trajectories for the industries they operate in, and then decide which presents the better opportunity.

For growth-oriented investors looking to tap into potentially explosive trends, building positions in both companies could be worthwhile. DraftKings and Roblox are high-risk, high-reward stocks that have the potential to be huge winners if they remain at the forefront of their respective niches.