The billionaire apologised on Wednesday for publishing a tweet earlier this month which supported an antisemitic conspiracy theory.
But in a message to advertisers who left the platform over the furore, Musk said: “If somebody's gonna try to blackmail me with advertising, blackmail me with money? Go f*** yourself.
"Go. F***. Yourself. Is that clear? I hope it is. Hey, Bob, if you're in the audience," he added, in an apparent reference to Robert Iger, chief executive of Walt Disney, which pulled ads on X, saying its association with X “was not a positive one for us".
"What I care about is the reality of goodness, not the perception of it. And what I see all over the place is people who care about looking good while doing evil. F*** them," Musk said.
The Tesla CEO had previously endorsed a post by a user which falsely accused Jewish people of “hatred against whites”, saying the user was speaking “the actual truth”.
On Wednesday, the entrepreneur said it was possibly his worst-ever post on the platform, which contained many “foolish” comments, and that he had "handed a loaded gun" to detractors.
Musk's post drew condemnation from the White House for what it called an "abhorrent promotion of antisemitic and racist hate."
Following the post, major US companies including Walt Disney, Warner Bros Discovery and NBCUniversal parent Comcast suspended their ads on X.
Musk said that X could fail financially as a result of the ad boycott.
“If the company fails because of advertiser boycott, it will fail because of an advertiser boycott,” he said.
“And that will be what bankrupt the company and that's what everybody on earth will know. Let the chips fall where they may."
In the wake of the condemnation around his post, Musk travelled to Israel and toured the site of Hamas' assault in the country on October 7.
On Monday, he spoke with Israeli Prime Minister Benjamin Netanyahu in a live-streamed conversation on the platform.
He said the trip had been planned before his message and was “independent" of the antisemitism backlash.
While in Israel, he said he was against antisemitism and anything that “promotes hate and conflict”.
He also received a symbolic dog-tag from the father of an Israeli hostage taken captive by Hamas, which he promised to wear until all the hostages were free.
He wore the dog-tag on stage during Wednesday’s New York Times DealBook Summit interview.