Why Lumentum’s stock led the S&P 500 higher on Monday

Lumentum led the S&P 500 higher on Monday as optical stocks staged a broader comeback. The move followed Anthropic's IPO filing and other positive news that helped lift sentiment across the optical sector, of which Lumentum is a part.

Optical companies supply the components and subsystems that underpin high-speed data transmission, making them sensitive to shifts in demand for data-center and networking capacity. When sentiment around major technology platforms improves, shares of suppliers tied to that infrastructure can react quickly. Monday's session illustrated that dynamic, with Lumentum outpacing the wider index.

For observers, the key question is whether the rebound reflects durable demand signals or a short-term sentiment shift. The Anthropic filing is a notable catalyst because it draws attention to the capital flowing into artificial intelligence, which in turn shapes expectations for the networking hardware that supports it. Watching whether optical names hold their gains, and whether follow-through appears in order trends and guidance, will offer a clearer read on whether this is more than a one-day move.