On June 26, fifteen trading days after its IPO, SpaceX qualified for the Nasdaq-100 under the index's fast-entry rule. Inclusion was effective before the open on July 7 — which, in practice, means the index-tracking complex (QQQ chief among it) did its buying into the July 6 closing auction. Passive funds do not chase an opening print; they contract with index-arbitrage desks for guaranteed execution at the close, and the desk works the order at its own risk. The transaction is the close before the effective date, not the session after it.
J.P. Morgan estimated roughly $4.3B of mechanical demand from Nasdaq-100 trackers, with broader estimates including Russell reweighting running to the $22–27B range. Whatever the exact figure, it was buying by mandate — funded by pro-rata trims of Nvidia, Apple, Microsoft, Amazon, and Alphabet — and it was, by the date it printed, the most public trade in the market.
Which is the point the note was written to make: an announced index flow is the most front-run event in equities. Arbitrage desks were positioned within minutes of the June 26 announcement; the academic record finds the once-famous “index effect” largely competed away. Tesla's own 2020 S&P inclusion — a run-up into the effective date, then a give-back the next session — is the template. The value of mapping a flow is not the flow itself, which everyone can see, but knowing what is already in the price, so one is not the liquidity the professionals are waiting for.