Bluesky has accumulated over 7 million new users in the two weeks since the U.S. presidential election, and now has over 21 million users.

Bluesky has surged in popularity since the presidential election earlier this month, suddenly becoming a competitor to Elon Musk's X and Meta's Threads. But CEO Jay Graber has some cautionary words for potential acquirers: Bluesky is "billionaire proof."

In an interview on Thursday with CNBC's "Money Movers," Graber said Bluesky's open design is intended to give users the option of leaving the service with all of their followers, which could thwart potential acquisition efforts.

"The billionaire proof is in the way everything is designed, and so if someone bought or if the Bluesky company went down, everything is open source," Graber said. "What happened to Twitter couldn't happen to us in the same ways, because you would always have the option to immediately move without having to start over."

Graber was referring to the way millions of users left Twitter, now X, after Musk purchased the company in 2022. Bluesky now has over 21 million users, still dwarfed by X and Threads, which Facebook's parent debuted in July 2023.

X and Meta didn't immediately respond to requests for comment.

Threads has roughly 275 million monthly users, Meta CEO Mark Zuckerberg said in October. Although Musk said in May that X has 600 million monthly users, market intelligence firm Sensor Tower estimates 318 million monthly users as of October.

Bluesky was created in 2019 as an internal Twitter project during Jack Dorsey's second stint as CEO, and became an independent public benefit corporation in 2022. In May of this year, Dorsey said he is no longer a member of Bluesky's board.

"In 2019, Jack had a vision for something better for social media, and so that's why he chose me to build this, and we're really thankful for him for setting this up, and we've continued to carry this out," said Graber, who previously founded Happening, a social network focused on events. "We're building an open-source social network that anyone can take into their own hands and build on, and it's something that is radically different from anything that's been done in social media before. Nobody's been this open, this transparent and put this much control in the users hands."

Part of Bluesky's business plan involves offering subscriptions that would let users access special features, Graber noted. She also said that Bluesky will add more services for third-party coders as part of the startup's "developer ecosystem."

Graber said Bluesky has ruled out the possibility of letting advertisers send algorithmically recommended ads to users.

"There's a lot on the road map, and I'll tell you what we're not going to do for monetization," Graber said. "We're not going to build an algorithm that just shoves ads at you, locking users in. That's not our model."

Bluesky has previously experienced major growth spurts. In September, it added 2 million users following X's suspension in Brazil over content moderation policy violations in the country and related legal matters.

In October, Bluesky announced that it raised $15 million in a funding round led by Blockchain Capital. The company has raised a total of $36 million, according to Pitchbook.