WASHINGTON >> Meta CEO Mark Zuckerberg emphasized in federal court on Wednesday that he bought Instagram and WhatsApp because he saw value in the companies — not to take out competitors, as the Federal Trade Commission alleges in a historic antitrust trial.

Zuckerberg took the stand for the third day in the trial, wrapping up his testimony as the first witness Wednesday afternoon. He took questions from Meta attorney Mark Hansen, who has argued that his client hardly has a monopoly in social media, as the FTC claims, and still faces stiff global competition.

Hansen focused some of his questioning on emails sent by Zuckerberg and his associates that the FTC cited in earlier testimony to illustrate the Facebook founder’s alarm over the growth of Instagram and his sense that he needed to neutralize its threat.

Zuckerberg said he’s very focused on inventing new things, and understanding what other people are creating is a big part of the process. At any given point in his company’s history, he said, similar tones of concern could be found in emails about what other companies were doing better than his.

Hansen questioned Zuckerberg about competition, particularly from TikTok, the popular social media site owned by Beijing-based company ByteDance, and the the growth of the video-sharing platform YouTube, which is owned by Alphabet.

Zuckerberg testified that people spend more time on YouTube than on Facebook and Instagram combined.

While Hansen noted that the FTC doesn’t consider YouTube to be a Meta competitor — because it doesn’t have the same friend-sharing technology as Facebook — Zuckerberg said YouTube has built in ways to share videos.

The FTC contends Meta has used a monopoly in its technology that facilitates connecting with friends and family to generate enormous profits as consumer satisfaction has dropped. The case could force the tech giant to break off Instagram and WhatsApp, startups it bought more than a decade ago that have since grown into social media powerhouses.