Coherent vs Lumentum: Who Wins the AI Light Race?
Both have $2 billion Nvidia investments. Both make optical modules for AI. One is growing 90%. The other is growing 20%. The market treats them as the same trade — they're not.
Revenue growth gap, same quarter
70 pp
▲ +70 LITE +90% YoY vs COHR +20.5% YoY
Coherent and Lumentum fell together this week — down 3% and 11% respectively. The market lumps them into one "AI optics" basket. But Lumentum just posted 90% year-over-year revenue growth and joined the Nasdaq-100. Coherent posted 20% growth and is watching its industrial segment shrink. Same Nvidia partnership. Same sector. Very different businesses.
The contradiction
The market sold both names this week as if they were one basket. The growth profiles say otherwise: one is being transformed by AI, the other is learning it.
What the headline says
The market narrative
"Same trade — AI optics"
What the data says
Revenue growth, most recent quarter
LITE +90% vs COHR +20%
Chapter 01
The market sold them as one trade. They're not.
Coherent fell 3% and Lumentum fell 11% this week. Same basket, same selloff — but the fundamental profiles diverge by 70 percentage points of revenue growth.
This week the optical basket sold off together. Coherent dropped three percent in five days. Lumentum dropped eleven. If you only looked at the sector heat map, you would see two red squares in the same row and assume the same story. But the story underneath is completely different. Lumentum just reported fiscal Q3 revenue of eight hundred and eight million dollars — up ninety percent year over year. Coherent reported one point eight one billion — up twenty point five percent. Both are growing. Both are tied to AI data-center demand. But one is accelerating at four and a half times the rate of the other. The seventy-percentage-point gap between their growth rates is the single most important number for any investor choosing between them.
"Both are growing. Both are tied to AI. But one is accelerating at four and a half times the rate of the other."
YoY revenue growth, most recent quarter
Source: Company filings: LITE Q3 FY26, COHR Q3 FY26
LITE Q3 revenue
$808M+90% YoY
COHR Q3 revenue
$1.81B+20.5% YoY
Growth gap
70 ppsame sector, same week
Chapter 02
Lumentum: the purest AI acceleration story in optics
Revenue up 90% YoY, capacity sold out through 2028, just joined the Nasdaq-100, and analysts expect $1.25B/quarter by year-end.
Lumentum's investment case is straightforward. Revenue grew ninety percent year over year to eight hundred and eight million dollars. Non-GAAP operating margin hit thirty-two percent. The company told investors its optical capacity is effectively sold out through 2028 — meaning every transceiver it can manufacture already has a buyer. Nvidia invested two billion dollars in equity and signed a long-term supply agreement. And on May 18, Lumentum joined the Nasdaq-100, which triggers forced buying from every index fund that tracks it. Rosenblatt expects quarterly revenue to reach one point two five billion by the end of 2026 and two billion by the end of 2027. If those numbers land, the annual revenue run-rate goes from roughly three point two billion today to eight billion in eighteen months. That is an acceleration trajectory more common in software than in hardware.
5-day price return: how the selloff hit each name
Source: MarketDecode price feed, May 19, 2026
LITE quarterly rev
$808M+90% YoY, 32% margins
Capacity lock-up
Through 2028sold out
Index inclusion
Nasdaq−100effective May 18
Chapter 03
Coherent: the platform play with an industrial drag
Bigger revenue ($1.81B), vertical integration into InP lasers, Nvidia $2B deal — but industrial segment declined from $529M to $444M and now drags the growth rate.
Coherent is a different kind of business. Total revenue is more than double Lumentum's at one point eight one billion per quarter. The company doesn't just make transceivers — it makes the indium phosphide lasers themselves, the substrate materials, and the packaging. That vertical integration is its moat: if you need InP capacity in a shortage, Coherent controls the supply. Nvidia made the same two-billion-dollar equity investment in Coherent as it did in Lumentum, plus a multi-year supply agreement. Analysts at TD Cowen, Rosenblatt, and Stifel all raised price targets after the quarter. But there is a drag. The Datacenter and Communications segment grew forty-one percent and now accounts for seventy-five percent of revenue. That is good. The industrial segment shrank from five hundred twenty-nine million to four hundred forty-four million — a sixteen percent decline. Coherent is a laser and materials company that is rapidly BECOMING an AI company. Lumentum already IS one.
"Coherent is a laser company that is rapidly becoming an AI company. Lumentum already is one."
COHR revenue by segment, Q3 FY26
Source: Coherent Corp Q3 FY26 earnings release
AI revenue share
75%DC/Comms segment
Industrial trend
−16% YoY$529M → $444M
Analyst PT range
$395–$425TD Cowen / Rosenblatt
Chapter 05
The verdict: LITE for growth, COHR for platform optionality
Lumentum is the cleaner, higher-beta AI optics play. Coherent is the bigger, more diversified platform with industrial drag but InP laser control.
Here is the honest read. If you want the purest exposure to AI optical acceleration — the name that is growing fastest, has the clearest capacity lock-up, and just got the index-inclusion tailwind — that is Lumentum. Ninety percent growth, sold out through 2028, Nasdaq-100 forces passive buying. The risk: it is priced for perfection. Any stumble on the path from eight hundred million to one point two five billion quarterly revenue, and the stock reprices violently. Vol is one hundred percent annualized. If you want the platform with more optionality — vertically integrated into InP lasers, bigger revenue base, lower volatility at eighty-two percent — that is Coherent. The risk: the industrial segment is shrinking, which drags the headline growth rate and creates a "two businesses" discount. Analysts are raising targets but the stock trades AT the mean PT today (three sixty-three vs PT three seventy-six). Both are bets on the same underlying demand signal: that AI clusters need more optical links every quarter. The difference is the purity of that exposure.
"Both are bets on the same demand signal. The difference is the purity of that exposure."
20-day volatility: torque vs floor
Source: MarketDecode price feed, May 19, 2026
LITE verdict
Growth play90% rev growth, 100% vol
COHR verdict
Platform bet20% growth, 82% vol, InP moat
COHR vs PT
$363 vs $376at consensus — limited upside
Chapter 06
Tomorrow is the grading event for both
Nvidia reports Q1 FY27 on May 20. Data-center revenue and optical networking commentary will move both COHR and LITE together — then the stocks diverge again on execution.
The single event that matters most for both names arrives tomorrow. Nvidia reports fiscal Q1 2027 on May 20. If data-center revenue accelerates or holds above forty billion dollars, the optical demand thesis is confirmed for both Coherent and Lumentum simultaneously. If Jensen Huang mentions Spectrum-X Photonics, co-packaged optics capacity, or transceiver lead times, both stocks rally. They will move together on the headline. Where they diverge is on execution in the months after. For Lumentum, watch: can quarterly revenue reach one billion by Q4 2026? That is the Rosenblatt milestone. For Coherent, watch: does the industrial drag stabilize, or does it keep shrinking and diluting the AI growth rate? Specific levels: LITE sits at RSI 48 — approaching oversold at 30. It is four percent below its 20-day SMA. COHR sits at RSI 60, nearly five percent above its SMA — the healthier technical position. If Nvidia delivers tomorrow, LITE likely bounces harder (higher beta). If Nvidia disappoints, COHR likely holds up better (lower vol, platform diversification).
"They will move together on the Nvidia headline. Where they diverge is on execution in the months after."
Distance to 20-day average
Source: MarketDecode price feed, May 19, 2026
Grading event
NVDA May 20tomorrow — Q1 FY27
LITE if NVDA beats
Higher bouncehigher beta, more extended
COHR if NVDA misses
Better floorlower vol, diversified
Resolution window — 1 week
What would confirm or invalidate this read
Confirmation
Nvidia Q1 FY27 data-center revenue confirms demand, AND LITE outperforms COHR by >5% in the 5 trading days after earnings (validating the "purer acceleration" thesis).
Invalidation
COHR outperforms LITE by >5% post-Nvidia (suggesting the market is pricing platform optionality over pure growth), OR both names make new 5-day lows regardless of Nvidia results.