Despite second- and third-quarter financial results that weren't immediately well-received by the investment community, Roku (ROKU -3.08%) shares have been on the way up in recent months, rising 52% since early August. That gain is better than the broader market indices.

However, as of Dec. 18, this growth stock was still trading 84% off its all-time high, a record that was set in July 2021. Does the dip mean you should buy Roku while it's below $90 per share, a level the shares were last at in February?

What the bulls think

Roku offers a smart-TV operating system that allows viewers to aggregate all of their various streaming services into a single user interface. The company has been doing this since 2008. Its lead in this industry has resulted in top market share in the U.S., as well as in Canada and Mexico.

Because the TV is vital to how households view video entertainment, this puts Roku in an advantageous position. In the third quarter, the company revealed that 32 billion hours of content were streamed on the Roku platform, up 20% year over year.

Another bull case centers on Roku's improving financial picture. Roku reported a $531 million and $792 million operating loss, respectively, in 2022 and 2023. But management has been focused on cutting costs. The operating loss shrank drastically from $350 million in Q3 2023 to $36 million last quarter, thanks to much lower research and development and sales and marketing costs.

Owning unprofitable companies is always a risk, because it demonstrates that the business model isn't sustainable yet. What's more, it puts Roku in a tough position if it has to raise capital at inopportune times. But it's worth pointing out that Roku's balance sheet looks clean. As of Sept. 30, the company had $2.1 billion in cash and cash equivalents with zero debt.

Investors might also consider buying this stock because Roku operates in two large and growing end markets, namely streaming entertainment and digital advertising. Every year, more households in the U.S. and worldwide decide to cancel their cable-TV subscriptions. And as engagement on these streaming platforms grows, advertising dollars are set to follow.

Risk factor

Of course, no matter how compelling the bull case is, investors always need to be mindful of risks that are present. Roku might have a dominant position among streaming platforms. But competition is incredibly fierce.

Just look at the heavyweights Roku goes up against. Apple has streaming service Apple TV+, as well as the platform Apple TV. In addition to the Chromecast and Google TV Streamer, Alphabet also owns YouTube and YouTube TV, two very popular video entertainment offerings. Then there's Amazon, which has Prime Video and Fire TV Sticks.

On the bright side, streaming might be too small an opportunity for these tech behemoths to plow more attention, effort, and resources toward to give Roku an even harder time. On the other hand, they all have unlimited financial resources to continue investing in technology and content to drive engagement. Plus, they have adeptness when it comes to digital advertising.

Expectations are low

It's challenging to recommend buying and holding a company that has to go head-to-head with some of the most powerful companies on the face of the planet. However, Roku is in the lead in the key North American market.

I believe the valuation is too hard to ignore right now. Shares trade at a price-to-sales ratio of 2.9, which is less than one-third the average multiple historically. Risk is somewhat reduced thanks to the attractive price tag, making Roku a smart stock to buy at below $90 per share.