Cathie Wood and ARK Invest haven't had a fantastic year. Year to date, shares of the staple ARK Innovation ETF (ARKK -3.26%) have dropped over 50%. Over five years, the Innovation ETF is now only beating the market by 3%, whereas it was thumping it by roughly 400% in early 2021.

However, Wood is still doubling down on quality stocks. Some of these high-flying tech stocks might be out of favor now, but the businesses are still posting durable results, giving long-term investors like Wood great opportunities. Specifically, she has recently loaded up on shares of Roku (ROKU -6.60%) and Unity Software (U -5.55%). Here's why you might want to follow suit.

1. Roku

Roku is one of ARK Invest's largest holdings across all its ETFs. When combining the firm's six ETFs, Roku is its third-largest position. This position is growing, too. Since June 10, ARK Invest has bought more than 184,000 shares of Roku, signaling its conviction in the long-term future of this streaming platform. 

ARK might have loaded up after seeing some of Roku's recent news: In June, Roku partnered with Walmart to bring shoppable e-commerce ads to the streaming space. With this partnership, Roku users can now buy Walmart products directly on Roku without being sent to a third-party site. This partnership eases the friction between advertisement and purchase, which should dramatically boost the value of Roku's ad space if this endeavor thrives. Roku's average revenue per user currently sits at $42.91, but the chances of advertisers paying up to have these shoppable ads are high if the Walmart ads succeed.

ARK was also likely fond of Roku's recent partnership with NBCUniversal (owned by Comcast) to bring live news to its users. The Roku Channel -- a top-five channel in the U.S. in terms of reach and engagement in Q1 on the Roku platform -- will now offer local news streaming in major U.S. cities like Los Angeles and New York City. Big streamers, namely Netflix, have largely avoided live news, which increases The Roku Channel's appeal to users.

This likely isn't the last of Roku's innovations. The company generated $183 million in free cash flow and $140 million in net income during the trailing 12 months, so it has enough money to remain the top dog in the streaming space in North America. 

At only 4.5 times sales, Roku is trading at its lowest valuation since 2018. Considering the success it has seen in new verticals -- in addition to its stable dominance as the largest streaming platform in North America in terms of hours streamed -- Roku looks like a bargain today. Wood has recently taken advantage of it, and you might want to do the same.

2. Unity Software

This company also trades at an appealing multiple of 10.7 times sales, which is nearly 58% lower than the valuation it came public at in 2020. While some investors might say Unity is a value trap, this looks more like a bargain opportunity to buy an industry leader at a cheap price. 

More than 1.5 million monthly active creators trust Unity to help them build, expand, and monetize their video games. In a study done by the company, 61% of respondents said they used Unity, showing its dominant grip. Other estimates put the company's market share at 48%, with the second-place competitor having just 13% share. However you slice it, Unity is a top dog in the game development space, which could allow it to capitalize on what is expected to be a $300 billion market by 2027.

However, Unity is not just a game development company. Its products can also help businesses plan, build, and experiment with ideas in digital worlds before putting them into action in real life. This reaches into industries like construction, automotive, aerospace, and even retail. For example, Unity can allow retailers to simulate store plans to optimize space and product placement, all before the store is even built.

Wood has seen Unity's leadership in the gaming industry and its potential in other areas, and she must like what she sees. Since June 10, ARK Invest has bought over 281,000 shares of Unity. The company has stumbled with its monetization products recently, but if you have a diversified portfolio that can take on some risk, Unity might be a company to buy and hold for the long term.