Anthropic's IPO filing names 5 music publisher lawsuits and warns a fair use loss could force it to retrain its models

Anthropic’s IPO prospectus is public, and the music publishers’ lawsuits are in it by name. The company filed its S-1 with the SEC on October 26, 2026, and its risk factors list 5 lyrics cases, from Concord Music Group to Sony Music Publishing.

Anthropic doesn’t put a number on any of them. The filing says the music publisher complaints “seek unspecified amounts of damages” and that the matters “are in preliminary stages.”

The money side: $16.3 billion in revenue for the first 6 months of 2026, up from $1.2 billion a year earlier, and a net loss of $42.0 billion for 2025. Anthropic has applied to list on the Nasdaq Global Select Market under the symbol “ANT,” and the price range is still blank.

I went through the S-1 on EDGAR myself. By my count, the risk factors run 69,911 words over more than 90 pages, which matches Music Ally’s “just under 70,000 words.”

Music Ally also reports that the IPO could value Anthropic at $1.5 trillion to $2 trillion and raise as much as $100 billion. The S-1 itself states neither number. It’s the public version of the confidential draft Anthropic filed in June.

The 5 music publisher lawsuits Anthropic’s S-1 names as an IPO risk

The names sit in a risk factor about intellectual property claims, on page 92, right after the $1.5 billion settlement with book authors. The filing says “various publishers have filed suit against us alleging copyright infringement of song lyrics and unlawful removal of copyright management information.”

The 5 cases it names, in the filing’s order:

• Concord Music Group, Inc., et al. v. Anthropic PBC, the 2023 lyrics case.
• Concord Music Group, Inc., et al. v. Anthropic PBC et al., the $3 billion case over pirated sheet music.
• BMG Rights Management (US) LLC v. Anthropic PBC.
• Round Hill Music LP, et al. v. Anthropic PBC.
• Sony Music Publishing (US) LLC v. Anthropic PBC et al., the complaint that names Dario Amodei and Benjamin Mann.

Then come 2 words: “and others.”

The legal matters note to the financial statements fills in more. It lists Concord Music Group, Universal Music Publishing Group, ABKCO Music, BMG, Round Hill Music, Sony Music Publishing and Warner Chappell as plaintiffs in suits filed between January and October 2026, calls them the “Music Publisher Matters,” and says certain of the complaints “also name two Company executives as defendants.” The S-1 doesn’t say which executives.

The 2 newest suits don’t appear by name. Reservoir sued Anthropic on October 21 over 853 lyrics, and Elvis Presley’s rights owners sued on October 23 over 274 songs. Both fall inside the S-1’s January-to-October window, so if Anthropic counts them, they’re under “and others.”

The oldest of the 5 is also the furthest along.

What Anthropic’s S-1 says about Concord v. Anthropic and the October 21 hearing

The S-1 calls the 2023 case “Concord I.” The publishers filed it in October 2023 in Tennessee, and it moved to the Northern District of California later. Anthropic sums up the claim in one line: that it “unlawfully copied and disseminated copyrighted lyrics controlled by the publishers.”

The filing is up to date on this one. “Both parties filed motions for summary judgment and the court held a hearing on October 21, 2026,” it says. That’s the hearing where Judge Eumi Lee weighed fair use on the lyrics to 499 songs, and she hasn’t ruled.

If the publishers win, damages come next, and US copyright law allows up to $150,000 a song for willful infringement. That’s statutory damages: a fixed amount per work that a court can award without the owner proving what they lost. The S-1 flags it on its own: “The possibility of statutory damages under some intellectual property legal frameworks creates additional risk for us.”

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We are vigorously defending ourselves in these pending lawsuits and believe we have meritorious defenses, though these lawsuits address novel issues and areas of law that make the results uncertain.

So what happens to Claude if Anthropic loses on fair use? The S-1 answers that too.

Anthropic’s S-1 on fair use: licensing fees or retraining models from scratch

Fair use is the part of US copyright law that lets you use someone’s work without permission in some cases, and it’s Anthropic’s main defence. The S-1 says Anthropic’s “good faith belief” that it has the rights to its training data rests “in part” on fair use.

If a court disagrees, the filing spells out 2 outcomes. First, “we may be required to pay significant fees to obtain a license to such training data.” Second, an adverse ruling “could require us to retrain affected models from scratch at substantial cost.” Retraining from scratch means building a model again without the data in dispute.

That ruling doesn’t have to come in an Anthropic case. The S-1 says an adverse ruling “against us or another company in our industry” could trigger it, and that rulings involving other AI developers could set precedent “regardless of the specific facts, data practices, or legal theories at issue in those cases.” It doesn’t name any other company.

Anthropic’s S-1 prices the $1.5 billion Bartz settlement but not the music suits

The book authors’ class action, Bartz v. Anthropic, is the one copyright case the S-1 puts numbers on. Anthropic settled it for $1.5 billion plus interest, the court approved the deal in July 2026, and Anthropic paid $300 million in 2025. On June 30, 2026, it still carried $1.2 billion of it as a current liability.

The music cases get none of that. Universal Music Publishing Group, Concord and ABKCO asked for $3 billion in the sheet music case, but the S-1 describes the Music Publisher Matters only as seeking “unspecified amounts of damages” and gives no loss estimate. Its general line on that: where it gives no estimate, “such an estimate is not possible or is immaterial.”

The S-1 also lists disputes that haven’t reached court. Anthropic says it has received notices and demands from rights-holders, including “book, news, and music publishers,” and that “some Rights-Holders have also sought to have their content removed from the Company’s training corpus.” It expects more, which “may ultimately result in litigation.”

Here’s what’s still open. The price range in the S-1 is still blank, and Judge Lee hasn’t ruled on fair use in the 2023 lyrics case. Motions to dismiss parts of the $3 billion case were set for a November 4 hearing.