Coherent's 79% Datacenter Mix Raises Sustainability Questions

What happened

In early September, Zacks highlighted that Coherent's datacenter revenue now accounts for 79% of the total, up from 75% in the March quarter, reinforcing the company's reliance on AI networking demand. The company continues to expand capacity and improve gross margins, but the article questions whether hyperscaler spending and execution can sustain the current growth momentum. Coherent's latest master report, as of July 2, 2026, maintained a WAIT rating with a stock price of $333.36 and no margin of safety, given that the valuation already assumes flawless AI optics ramp and capacity conversion. The new article adds a modest update to the concentration metric but does not resolve the core risks of inventory buildup and weak cash conversion that could derail the story. Overall, the operating momentum is intact, but the market narrative is crowded and the bar for upside remains high.

Implication

The article does not change the fundamental picture that Coherent is a strong operator with a real technological edge, but valuation remains demanding. Given that the stock trades near 146x earnings and 49x EV/EBITDA, any hiccup in hyperscaler deployment or capacity ramp could trigger a sharp de-rating. The increase in datacenter mix from 75% to 79% means the company is even more leveraged to AI networking demand, making it vulnerable to capital spending pauses or pushouts. Investors should wait for evidence that the 6-inch indium phosphide expansion translates into sustained margin improvement and free cash flow generation, rather than just revenue growth. The current level does not offer a sufficient margin of safety, so the appropriate stance is to hold off on new positions until the stock pulls back toward the ~$285 attractive entry zone or until quarterly results prove stronger cash conversion.

Thesis delta

The master report's WAIT rating is unchanged because the new article provides no new financial details beyond the slightly higher datacenter mix. The 79% figure reinforces the concentration risk already flagged, but does not alter the valuation or execution concerns. The key question shifts from whether demand exists to whether Coherent can convert it into profitable shipments without margin slippage.