As Bloomberg reports, citing analysts and brand agencies, the social messaging service’s new owner erased as much as $20 billion in value with the move.

By way of some explanation, Musk wrote in a tweet: “The Twitter name made sense when it was just 140 character messages going back and forth–like birds tweeting–but now you can post almost anything, including several hours of video. In the months to come, we will add comprehensive communications and the ability to conduct your entire financial world.”

Top marketers’ initial reception of the X rebrand has been frosty. As Matt Egan, managing director of strategy at brand experience firm Siegel+Gale, told Marketing Brew, “My first reaction was, ‘Is this a joke?’...Honestly, I think it’s idiotic.”

As CMSWire notes, the X backlash highlights the short time frame marketing pros face in disseminating the messaging from a rebrand. Musk has been hyping up the X concept for years, but when he finally got around to applying the name to Twitter, it landed with a thud.

The change also shows the risks of a brand name with a vague meaning, according to CMSWire. A name like X is associated with so many ideas that consumers may be left shaking their heads—or shrugging.

Musk’s decision also illustrates the importance of weighing legal considerations before embarking on a rebrand. Meta and Microsoft are reportedly among the companies with legal grounds to challenge Twitter’s embrace of the letter X.

As Inc. reports, the episode also demonstrates the need to conduct thorough customer research before a big brand change. Companies also need to be prepared to explain their rationale clearly and effectively, according to the publication.

Becca Marchant, social associate director at M&C Saatchi Talk, told Little Black Book, “Whether X is the next step in the future of social media or Musk’s own personal branding exercise will remain to be seen but as brands have already cut Twitter from their media budgets, this rebrand puts the platform’s future into even more danger.”