When artificial intelligence company Anthropic (ANT.US) begins trading after its expected listing next week, how its share price performs in the first few weeks will depend mainly on who has to buy, not who wants to buy.
Investors are studying the process of SpaceX's successful listing in June this year, looking for clues. Elon Musk's SpaceX (SPCX.US) rewrote the established playbook for giant company stock listings: major U.S. index providers such as Nasdaq rewrote their inclusion rules to ensure a large pool of passive funds would buy the stock within the first 15 days after its listing.
Investors expect the same dynamic to play out for Anthropic. The developer of the Claude chatbot plans to issue 825 million shares at $70 to $78 per share, raising up to $64.4 billion, with a company valuation of up to $1.4 trillion.
In the past, major index providers typically waited weeks or months after a company's listing before adding it to benchmark indices. But like SpaceX, Anthropic will be included in at least six major indices within 5 to 15 days after listing, including the FTSE USA Index, the S&P Total Market Index and the Nasdaq 100.
"Anthropic is the mirror image of the SpaceX IPO. In that respect, it has the same index-related drivers as SpaceX during its first 15 days of trading," said Carsten Hesse, head of index events at Berenberg in London.
London-based index rebalancing analysis firm Intropic estimates that passive demand from index-tracking funds will account for about 28% of Anthropic's issued shares, or roughly $19 billion. Funds conducting index rebalancing and hedge funds will bid to buy in advance to build positions before this expected passive demand emerges.
SpaceX reserved one-fifth of its $75 billion offering size for retail investors, more than double the normal level, at a valuation of nearly $1.75 trillion. Anthropic is doing the same thing. Index funds and retail investors together took nearly half of SpaceX's offered shares, while other fund managers built positions in advance to capture this demand. This created upward momentum for the small portion of shares in free float from the initial public offering. Similarly, Anthropic's IPO shares represent only about 6% of its total outstanding equity.
SpaceX and South Korean company SK Hynix, which listed on Nasdaq in July this year, both saw significant share price jumps on their third day of trading — the day options trading began, when speculators hedged derivative positions by buying the underlying stock. Analysts say similar early buying will occur with Anthropic's stock.
"You don't wait until day 5, day 10, day 15, until you see the index upgrade or inclusion actually take effect," Hesse said. "As we saw with SpaceX, people buy ahead of time."
A game changer for index trading
By the third day, SpaceX's share price had risen 50% cumulatively from its $150 opening price on the first day of trading, and remained well above its $135 offer price throughout the first 15 days. The stock later declined as investors began preparing for the first lock-up expirations, when employees and other pre-listing shareholders are permitted to sell.
Intropic equity analyst Ruben Pathmanathan said buying with very low price elasticity drove the rally. "The reason SpaceX may serve as a blueprint is that several market forces converged around the listing simultaneously: index inclusion, passive demand and a highly concentrated float. Together they determined how the stock was priced and how it traded in the first few days."
Anthropic's path may differ slightly: it is allowing employees holding about 15% of the company's equity to sell some shares on the first day of trading. Anthropic is also raising $26 billion through a separate private placement to cornerstone investors, including Google (GOOGL.US), Nvidia (NVDA.US) and AMD (AMD.US), and these shares have no lock-up period.
New index rules and massive fund flows have become a game changer for the funds that profit from index rebalancing trades. "This is an evolution of the market," said Brian Hartigan, head of global ETFs and index investments at Invesco, referring to the novelty of such mega-offerings that accumulate enormous private shareholdings before listing. Traditionally, index rebalancing trades have been constrained by IPO size — too many funds try to front-run, while passive demand is limited. For mega IPOs, this problem is less pronounced.
"This is the type of opportunity the arbitrage community likes, because crowding risk is relatively limited," said Celia Fseil, head of equity market-neutral strategies at Candriam. According to reports, two teams at Millennium Management engaged in index change trading made $3.7 billion in June. Millennium declined to confirm.
"If you do index rebalancing, these can be once-in-a-lifetime events," said Bill Park, chief investment officer at Connecticut-based Altisma Capital Management.
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