Lumentum Holdings Inc. to Join the Nasdaq-100 Index® Beginning May 18, 2026

This is a routine index reshuffle with minimal direct impact for most investors.

What the company is saying

Nasdaq is announcing that Lumentum Holdings Inc. (NASDAQ:LITE) will join the Nasdaq-100 Index, replacing CoStar Group, Inc. (NASDAQ:CSGP) before the market opens on May 18, 2026. The company frames this as a significant event by highlighting the scale and influence of the Nasdaq-100 Index, which is tracked by over 200 investment products and represents more than $600 billion in assets under management. The announcement emphasizes Nasdaq’s role as a leading index provider, referencing its maintenance of over 35,000 indexes and its global reach. The language is neutral and factual, with only mild promotional undertones when describing Nasdaq’s index business as “comprehensive” and “rules-based.” There is no mention of operational, financial, or strategic rationale for the index change, nor any discussion of the criteria or process behind the selection of Lumentum or the removal of CoStar Group. The communication style is formal and procedural, projecting confidence in the index’s stature but offering no forward-looking promises about performance or investor benefit. Notably, the announcement includes standard legal disclaimers that past performance is not indicative of future results and that actual outcomes may differ materially from expectations. No notable individuals with institutional roles are identified as participants or quoted, and the only named individual, Maximilian Leitenberger, has an unknown role and is not referenced in the main text. This narrative fits Nasdaq’s broader investor relations strategy of positioning itself as a neutral, authoritative market infrastructure provider, rather than as a promoter of individual index constituents. There is no evident shift in messaging compared to typical index change announcements; the tone and content are consistent with prior communications of this type.

What the data suggests

The disclosed numbers are limited but clear: the Nasdaq-100 Index tracks 100 of the largest Nasdaq-listed non-financial companies, is followed by more than 200 investment products, and has over $600 billion in assets under management globally. Nasdaq Global Indexes claims to publish and maintain more than 35,000 indexes across asset classes and geographies. The only forward-looking data point is the scheduled index change date—May 18, 2026—when Lumentum Holdings Inc. will replace CoStar Group, Inc. There are no financial results, earnings figures, or performance metrics for any of the companies involved, nor is there any disclosure of the index weighting, expected flows, or historical performance impact of similar changes. The gap between what is claimed and what is evidenced is minimal, as the announcement is strictly factual and avoids making unsupported projections. There is no reference to prior targets or guidance, and no indication of whether previous index changes have met or missed any stated objectives. The financial disclosures are high-level and complete for the purpose of an index change notice, but lack granularity for investors seeking to quantify the impact on Lumentum, CoStar, or the index itself. An independent analyst would conclude that this is a routine, scheduled index rebalancing with no immediate financial implications disclosed for any party.

Analysis

The announcement is a factual disclosure of an upcoming index composition change, specifying that Lumentum Holdings Inc. will replace CoStar Group, Inc. in the Nasdaq-100 Index on a set future date. The language is largely descriptive, with only minimal promotional phrasing about Nasdaq's index business. Most claims are realised facts (current index size, number of products, AUM, number of indexes), with only the index change itself being forward-looking, but scheduled and routine. There is no mention of capital outlay, synergies, or earnings impact, and no aspirational or exaggerated projections. The forward-looking statements are standard legal disclaimers, not promotional claims. The gap between narrative and evidence is negligible, as all material statements are supported by disclosed facts.

Risk flags

• ●Operational risk is minimal, as the index change is a routine administrative action, but investors in products tracking the Nasdaq-100 should be aware that constituent changes can trigger portfolio rebalancing and minor transaction costs.
• ●Disclosure risk exists in that the announcement provides no detail on the rationale for removing CoStar Group or adding Lumentum Holdings, leaving investors without insight into the selection criteria or potential future changes.
• ●Financial risk to individual investors is limited, but those holding significant positions in either Lumentum or CoStar Group may experience short-term volatility due to index-tracking fund flows around the effective date.
• ●Pattern-based risk is low, as there is no evidence of unusual or promotional behavior; however, the lack of historical context or performance data means investors cannot assess whether such index changes have historically benefited or harmed constituent companies.
• ●Timeline/execution risk is negligible, as the change is scheduled and procedural, but investors should monitor for any corporate events that could disrupt the planned substitution.
• ●Forward-looking risk is present in the sense that the majority of the announcement’s impact is tied to a future event (the index change), and there is no guarantee that inclusion in the index will benefit Lumentum’s share price or liquidity.
• ●Capital intensity risk is not directly relevant here, as there is no mention of capital outlay or investment required by any party, but the large AUM tracking the index means that even small changes can have outsized effects on constituent stocks.
• ●Geographic or factual inconsistency risk is absent, as no locations or ambiguous facts are presented; all claims are directly supported by the disclosed data.

Bottom line

For investors, this announcement is a straightforward notification of an upcoming change in the Nasdaq-100 Index: Lumentum Holdings Inc. will replace CoStar Group, Inc. on May 18, 2026. The narrative is credible and factual, with no hype or unsupported claims, and the only forward-looking element is the scheduled index change itself. No notable institutional figures are involved or quoted, so there are no additional signals to interpret from insider participation. To materially change this assessment, Nasdaq would need to disclose the specific criteria for the index change, the expected impact on index-tracking fund flows, or historical data on how similar changes have affected constituent companies. Investors should watch for any updates to the index composition, as well as trading volume and price action in Lumentum and CoStar Group around the effective date. This information is primarily of interest to those holding or considering positions in index-tracking products, or in the affected companies themselves; for most investors, it is a signal to monitor rather than to act upon. The most important takeaway is that this is a routine, rules-based index adjustment with limited direct implications for long-term investors, but it may cause short-term volatility in the stocks involved due to passive fund rebalancing.

Announcement summary

Nasdaq (Nasdaq: NDAQ) announced that Lumentum Holdings Inc. (Nasdaq: LITE) will become a component of the Nasdaq-100 Index ®, replacing CoStar Group, Inc. (Nasdaq: CSGP) prior to market open on Monday, May 18, 2026. The Nasdaq-100 Index ® measures the performance of 100 of the largest Nasdaq-listed non-financial companies and is tracked by more than 200 investment products with over $600 billion in assets under management globally. Nasdaq Global Indexes publishes and maintains more than 35,000 indexes across asset classes and geographies. This change may impact investment products and strategies that track the Nasdaq-100 Index ®.

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