Coherent's Margin Expansion is a Metric Investors Should Watch

Coherent’s adjusted operating margin expanded 163 bps year over year in Q3, helped by higher AI-related optical networking demand and improved factory utilization/supply chain efficiencies. Adjusted net income jumped nearly 56% YoY, reflecting operating leverage as fixed manufacturing costs were spread across rising volumes. The stock has surged 249% over the past year, though the forward 12-month P/E is elevated at 39.02x vs. 22.03x for the industry; Zacks consensus earnings for 2026 has declined over the last 60 days while the company retains a Zacks Rank #2 (Buy).

Analysis

This is primarily a margin-absorption story, not just an AI-demand story. In a fixed-cost optical manufacturing base, rising utilization can create disproportionate EPS upside for 1-2 quarters, but that leverage is also the first thing to fade if customer ordering normalizes or capacity expansion catches up. The market is likely to reward the inflection first and interrogate sustainability later, which is why the stock can keep working even as valuation screens look stretched.

The broader winner is the AI interconnect chain, but COHR is the cleanest expression because it combines demand visibility with operating leverage and lower balance-sheet risk than most photonics peers. LITE should get some sympathy if investors continue to re-rate the whole optical stack, while IPGP remains the weaker relative trade because it does not have the same AI mix or backlog optionality. A subtle second-order effect is that stronger COHR execution can tighten supply allocation across the chain, raising lead-time pressure for smaller competitors and potentially forcing them to accept less favorable pricing or lower-margin mix.

The contrarian point is that the market may be over-extrapolating backlog into 2026 earnings power even as estimates are still drifting down. That usually means the next catalyst is not another revenue beat, but evidence that margin expansion is durable despite higher volume and the need to invest in capacity. Falsifiers are simple: operating margin stalls, 2026 estimates keep falling, or AI capex commentary from NVDA-adjacent customers softens over the next 1-3 months. Over 6-18 months, the risk is that the stock has already priced in the best part of the utilization cycle.

Key Decisions for Investors

• Prefer a relative-value long COHR / short IPGP pair trade into the next earnings cycle: COHR has the cleaner AI exposure and margin leverage, while IPGP is less likely to participate in the rerating if optical demand remains concentrated in data-center interconnect.
• Do not chase COHR outright after the sharp multi-quarter rerating; wait for a 5-10% pullback or for 2026 estimate revisions to stabilize before adding exposure. If momentum persists, express via call spreads rather than stock to limit multiple-compression risk.
• Use LITE as a sympathy long only if sector multiple expansion broadens beyond COHR; otherwise treat it as a lower-beta laggard. Relative to COHR, LITE is the better hedge against single-name disappointment but the weaker vehicle for AI upside.
• Set a near-term alert on COHR guidance and gross margin, not just revenue: if operating margin fails to continue expanding next quarter, the thesis shifts from 'margin inflection' to 'peak utilization,' which would justify de-risking quickly.
• If you want broader AI-infrastructure exposure with less single-name execution risk, pair a small COHR position with NVDA rather than owning COHR alone; the trade works only if the ecosystem remains capex-intense and supply-constrained.