Traders tend to take it easy on the Friday before a holiday weekend, but ARK Invest CEO Cathie Wood is no run-of-the-mill money manager. She was actively buying and selling positions across her collection of high-growth exchange-traded funds.

What was she buying on Friday? Wood added to her positions in Roku (ROKU -2.67%), Zillow Group (Z 4.72%) (ZG 4.41%), and (JD -0.65%) on the final trading day of last week. Let's take a closer look at the shopping list. 

Someone on a couch holding a TV remote control.

Image source: Getty Images.


Shares of Roku came under pressure on Friday, as reports that Amazon (AMZN -0.68%) will enter the smart TV market rattled investors. Amazon and Roku have been competitors since the world's largest online retailer rolled out its Fire TV dongles in 2014. It took another page out of the Roku playbook two years later, when it started to partner with smart TV manufacturers to ship with its Fire TV operating system. 

The new development involves reports that Amazon could launch its own branded line of TVs later this year. It doesn't seem like a needle-moving decision, though, especially if Amazon finds some of its TV partners unhappy enough about competing with Amazon that they go with the agnosticism of Roku. More than a third of the new smart TVs sold in the U.S. come with Roku's operating system.

ARK Invest was lightening its position in Roku earlier this summer. Wood was selling the stock in late June and through all of July. She started buying again in August. On Friday, she added more Roku shares to a pair of her ETFs.

Zillow Group

Real estate is hot, but the same can't be said about the leading online portals in this booming niche. Zillow Group is trading at less than half of what it was fetching when it peaked in February, and Wood is taking advantage of the opportunity to pick up a market leader with its stock price down to double digits. 

Zillow's appeal is clear. It's reaching 229 million monthly unique visitors on its various platforms. Revenue soared 70% in its latest quarter, and it's not just Zillow's low-margin home-flipping business, Zillow Offers, that's doing the heavy lifting. Revenue also rose 70% if you exclude Zillow Offers. 

One can argue that the stock got ahead if itself when it soared above $200 earlier this year, but the platform itself has never been more popular than it is right now. The real estate market won't be scintillating forever, but Zillow's appeal should continue to grow for buyers and renters looking to make a move.

Growth investors have been trading out of China's former market darlings. Global tensions are mounting, and recent regulatory crackdowns in certain industries make investing in China riskier than ever. Wood isn't immune from the mindset, as she was dumping shares of this summer through early August. But her tune changed on after it reported blowout financial results late last month. She's been adding to her position over the past two weeks, including another purchase on Friday.'s 26% year-over-year revenue increase was impressive, given low market expectations. Adjusted earnings took a step back for the e-commerce giant but still landed well ahead of expectations. China is taking a hard stance on some businesses, including for-profit educators and online gaming, but it's not likely to put the brakes on commerce and e-commerce.