Lumentum is the dominant optical component supplier for AI data center interconnects, holding 50-60% market share in 200G/lane EMLs that power 800G and 1.6T transceivers, with capacity sold out through 2027. Q3 FY2026 (May 5) printed $808M revenue (+90% YoY, +21% QoQ) beating the $780-830M guide ceiling, and Q4 was guided $960M-$1.01B (non-GAAP EPS $2.85-$3.05) — sequential acceleration not deceleration. Now a dual-index constituent (S&P 500 3/23, Nasdaq-100 5/18) with NVIDIA $2B convertible preferred + multi-billion purchase commitment validating Lumentum as critical AI optical infrastructure. However, at $728.32 (re-anchored 2026-07-03, down 24.5% from the $964.82 5/22 anchor / 29% from the $1,028 Nasdaq-100 peak) the stock trades at ~46x CY2027E base-case non-GAAP EPS ($16) and ~90x FY2026E non-GAAP EPS (~$8.09) — the business is executing superbly, but the price still prices in OCS platform success AND CPO multi-customer expansion AND a structural dual-index premium before Q4 FY2026 (August) confirms the $1B/Q run-rate. The de-rate has compressed the probability-weighted loss from -35.6% to -12.6%: the acute-overvaluation Sell has largely played out, but at $728 the stock sits just above the $700 Hold re-entry threshold with risk still skewed to the downside (bear -58.8% vs bull +35.9%).