Lumentum to Join Nasdaq-100, Shares Rally 7.4% to Record Peak
Lumentum announced it will join the Nasdaq-100 index on May 18, replacing CoStar Group, triggering a 7.4% share rally and record peak. The stock is up 168% year-to-date while short interest fell 22.4% to 12.6% of float and volatility readings hit the 87th percentile.
1. Nasdaq-100 Inclusion
Lumentum will be added to the Nasdaq-100 index on May 18, replacing CoStar Group, marking a milestone in the company’s market recognition and potentially boosting index-linked fund buying.
2. Share Performance
Shares jumped 7.4% on the inclusion announcement, briefly reaching a record high before settling, and have climbed 168% so far in 2026 as AI-driven demand underpins growth expectations.
3. Short Interest Dynamics
Short interest declined 22.4% over the last two reporting periods, leaving 8.91 million shares sold short, equal to 12.6% of the float, which could amplify upward pressure if a squeeze unfolds.
4. Options Market Activity
Options traders have a put/call open interest ratio of 1.08, in the 87th percentile, while Lumentum’s volatility scorecard sits at 87 out of 100, reflecting historically higher-than-expected swings.