SpaceX Volume Hits 335M as Nasdaq-100 Weight Set to Double

Space Exploration Technologies traded 335.2 million shares on Friday, 18 September - roughly four times the 84.0 million that changed hands a day earlier, according to Yahoo Finance's daily series for the ticker SPCX. The stock settled at $152.71, down about 1.4% from Thursday's $154.81 close. Friday was the day the Nasdaq-100's September rebalance was priced in: under Nasdaq's published index methodology, the new weights take effect at the market open on the first trading day after the third Friday of September, which is Monday, 21 September.

How much bigger SpaceX's slice becomes is the part still being settled. Bloomberg reported on 12 September that pro forma data from Nasdaq's Global Index Watch pointed to a weight of about 2.82%, up from roughly 1.28% - more than double - while noting the final figure was due later in the month. Four days earlier, Bloomberg had reported a more conservative estimate from JPMorgan strategists led by Min Moon, who put the post-rebalance weight at 2.25%, up from 1.25%. The two numbers come from different methods and have not been reconciled.

The dollar stakes follow from the size of the money that tracks the benchmark. Bloomberg reported that roughly $1.7 trillion in assets tracked the Nasdaq-100 as of the end of the second quarter, including the Invesco QQQ Trust. JPMorgan's estimate implies about $15.5 billion of net passive buying; MarketBeat, writing on 15 September, put the likely range at $15.5 billion to $22 billion and said the adjustment would land at the 18 September closing bell. Funds that track an index do not get to choose - they buy because the benchmark changed, not because the business did.

The mechanism is a float rule most investors never see. Nasdaq's methodology says that "in order to preserve investability for low-float securities," a low-float company's total shares outstanding are capped at three times its free-floating shares when its weight is calculated. SpaceX listed on 12 June 2026 at $135 a share, per MarketBeat, and most of its stock was locked up, so the cap held its weight far below its market value - Bloomberg noted the company already ranks sixth by market capitalisation in the index. Bloomberg reported that more than a billion shares came free before the rebalance announcement. Nasdaq's calendar sets the reference date for a September rebalance as the last trading day of August, so those unlocks counted.

More is queued. Bloomberg reported that over a billion further shares unlock by the end of October and another 1.3 billion become tradable after third-quarter earnings in mid-November, which could push the weight up again at a later rebalance. SpaceX entered the index on 7 July under Nasdaq's Fast Entry rule for listings ranking in the top 40 of current constituents by full market capitalisation; the methodology says such a company is typically added about 15 trading days after its IPO. Nasdaq has not published the confirmed new weight.

This article is for information only and is not investment advice.