How Nasdaq weights a giant with little free float

A company’s market value can include substantial holdings that seldom trade. An index-tracking fund has to obtain shares from the available pool, commonly called the free float. Nasdaq’s 2026 changes to the Nasdaq-100 address that mismatch by using one measure of size to help select companies and another to determine their weight.

The changes followed a public consultation: a faster route into the index began on May 1, and the low-float weight adjustment was applied at the June 22nd quarterly review. Nasdaq described the purpose in its May explanation as keeping the benchmark representative and investable as ownership structures and public markets evolve. For funds whose purchases are tied to an index weight, the calculation affects how much stock they may need to obtain.

Two measurements of size

The methodology distinguishes full market capitalisation from modified market capitalisation. For ordinary non-ADR listings, the former includes listed and unlisted shares. For weighting, eligible listed share classes matter, and the share count for a low-float security is limited to three times its free-floating shares if that is below its reported total. A company can therefore qualify because of its full size while receiving a smaller allocation to reflect the shares available.

Consider a deliberately simplified company with 100 shares, only ten of which are freely floating. The three-times-float limit would restrict the share count used for that security’s weighting calculation to 30, assuming the other relevant conditions are satisfied. It would not release another 20 shares for trading. The remaining shares stay outside the freely traded pool; only their treatment in the weighting calculation changes.

If many funds need to buy from a small circulating pool at once, their orders can be large relative to the shares available. A lower index allocation may ease that pressure. The execution cost still depends on the prices at which existing holders are willing to sell and the amount of stock offered.

Fast entry, measured weight

Nasdaq also introduced an expedited entry route for sufficiently large eligible companies. The threshold is a full-market-capitalisation ranking within the top 40 current constituents. The formal rules say a fast entry need not remove an existing constituent immediately, allowing the count temporarily to exceed 100.

Faster inclusion and a constrained weight address different problems. An index may otherwise take time to reflect an important new public company. Yet including that company at a weight based on shares investors cannot readily acquire could make tracking harder. Combining the two changes recognises that prompt representation and practical ownership can pull in different directions.

The changes are also relevant beyond conventional index funds. A July 30 preliminary structured-product filing describes the revised methodology for investors whose repayment depends partly on the Nasdaq-100. Those investors may never hold a constituent directly, but a change in the benchmark’s construction can still change the economic exposure referenced by their product. The methodology helps define the exposure on which those repayment terms depend.

The exposure still has a defined scope

A float adjustment does not turn the Nasdaq-100 into an equal-weight index. Large eligible companies can still have much more influence than smaller ones. Nor does it make the benchmark a complete map of American equities: its stated remit concerns large Nasdaq-listed non-financial companies. Reading its movements as the verdict of every listed business would attach a broader meaning than its design supports.

Nasdaq’s March announcement establishes the decision and effective date. It does not establish that the changes improved realised liquidity, lowered tracking costs or produced better returns. Those outcomes require observations of trading and portfolios after implementation, with other market changes taken into account.

At the next index review, the full market value alone will not explain a low-float company’s allocation. The relevant comparison is with the eligible share classes and the free-floating share count used for weighting. The simplified 100-share company illustrates why: a benchmark can recognise the value of the whole business while limiting the demand it directs towards the ten shares freely available. That separation is the practical effect of the revised rule.