SpaceX shares may see buying surge from Nasdaq rebalancing as index weight triples

SpaceX’s stock has had a rough couple of months since its post-IPO euphoria faded, dropping roughly 31-34% from its peak of $225.64 to trade in the $147-$153 range. But a wave of forced buying may be heading its way, and it has nothing to do with rockets.

The Nasdaq-100’s quarterly rebalance, expected around September 21, is set to dramatically increase SpaceX’s weighting in the index. The company’s share could jump from about 1% to over 3.5%, a shift that would compel every fund tracking the index to mechanically load up on more stock.

Why the weight is about to jump

When SpaceX debuted on public markets with its June 12 IPO at $135 per share, the vast majority of its stock was locked up, restricted from trading. That limited public float kept its Nasdaq-100 weighting artificially low relative to its massive valuation, which landed somewhere between $1.75 trillion and $2 trillion.

Now those lockups are expiring in waves. The first tranche hit on August 6, releasing 911.5 million shares into the market. A second batch of approximately 378 million shares is set to unlock around September 9-10, just days before the rebalancing calculation takes place.

J.P. Morgan estimated that SpaceX’s initial Nasdaq-100 inclusion in July generated around $4.3 billion in passive inflows alone. The September rebalance, which more than triples the company’s index weight, could drive even larger sums into the stock.

The tug of war between insiders and index funds

There’s a natural tension embedded in this situation. The same lockup expirations that boost SpaceX’s index weight also let insiders and early investors sell for the first time. That creates potential selling pressure at the exact moment passive funds are being forced to buy.

SpaceX’s stock has already absorbed some of that pressure. The decline from $225.64 to the low $150s reflects early selling after the August 6 lockup release. The company raised approximately $85.7 to $86 billion in that offering, making it one of the largest IPOs in history.

Index-driven demand is non-discretionary. Fund managers tracking the Nasdaq-100 don’t get to decide whether SpaceX at $150 represents good value. They’re contractually obligated to match the index’s composition. When the weight goes up, they buy.

A new playbook for mega-IPOs

Fast-track rules implemented by index providers allowed SpaceX to join the Russell 1000 in late June, barely two weeks after going public, and the Nasdaq-100 on July 7. Historically, newly public companies had to wait for scheduled reconstitution dates, sometimes sitting in index limbo for months.

For passive investors holding Nasdaq-100 tracking funds like the Invesco QQQ, the rebalance means SpaceX will quietly become a much larger portion of their portfolio, with its weight rising from approximately 1% to over 3.5%.