The arms-dealer of the AI optics build-out — Lumentum owns ~50-60% of the 200G/lane EML laser chip that every 1.6T transceiver needs, NVIDIA just bought $2B of preferred to lock its capacity, and revenue is compounding ~90% YoY off a real telecom trough; but at ~52x forward earnings with two customers = ~40% of revenue and a $3.8B convertible stack now in-the-money, the price already discounts flawless execution.
| Date | Type | What happened | Source |
|---|
| 2026-08-10 | editorial note | Margin figure revised: 44.2% → 47.9%Margin moved from 44.2% (deep-dive-2026-06-18.md) to 47.9% (deep-dive-2026-08-10.md). | dossier |
| 2026-08-10 | editorial note | Revenue figure revised: $808.4M → $960MRevenue moved from $808.4M (deep-dive-2026-06-18.md) to $960M (deep-dive-2026-08-10.md). | dossier |
| 2026-08-10 | editorial note | Verdict changed: The arms-dealer of the AI optics build-out — Lumentum owns ~50-60% of the 200G/lane EML laser chip that every 1.6T transceiver needs, NVIDIA just bought $2B of preferred to lock its …Before (deep-dive-2026-06-18.md): The arms-dealer of the AI optics build-out — Lumentum owns ~50-60% of the 200G/lane EML laser chip that every 1.6T transceiver needs, NVIDIA just bought $2B of preferred to lock its capacity, and revenue is compounding ~90% YoY off a real telecom trough; but at ~52x forward earnings with two customers = ~40% of revenue and a $3.8B convertible stack now in-the-money, the price already discounts flawless execution. After (deep-dive-2026-08-10.md): The operating story got better and the stock got cheaper — supply still lags demand by more than 30%, the 2028 convert overhang was equitized in June, and Washington is drafting a ban on the Chinese modules that were the bear case — but the refresh also found the prior dossier's per-share math was too generous on both ends (FY26 non-GAAP EPS is ~$8.1, not ~$9.3, and the diluted base management guides to is ~102M, not ~96M), so at $834 this is still ~103x the fiscal year that ends tomorrow and ~45x next year's street number, with the single most information-dense event of the year landing 2026-08-11. | dossier |
The verdict
The operating story got better and the stock got cheaper — supply still lags demand by more than 30%, the 2028 convert overhang was equitized in June, and Washington is drafting a ban on the Chinese modules that were the bear case — but the refresh also found the prior dossier's per-share math was too generous on both ends (FY26 non-GAAP EPS is ~$8.1, not ~$9.3, and the diluted base management guides to is ~102M, not ~96M), so at $834 this is still ~103x the fiscal year that ends tomorrow and ~45x next year's street number, with the single most information-dense event of the year landing 2026-08-11.
Primary sources
SEC filings
Earnings calls
Source documents — open to read in full
The structural thesis stands, and on the operating side it strengthened. Every load-bearing claim in the prior dossier survives contact with the new material:
What weakened. Not the business — the per-share arithmetic and the duration of the moat. The share base is ~6% larger than the prior dossier modeled, FY26 non-GAAP EPS is landing ~12% below its estimate, and the industry is adding EML capacity on a schedule that now has a public number. Separately, a secondary source argues Coherent's proprietary 6-inch indium-phosphide platform yields more die per wafer at lower cost than Lumentum's smaller-wafer lines — flagged, not adopted: this is a substack claim, not a filing or a company statement, and Lumentum's own answer to capacity (a fifth fab) is on the record. It belongs on the watch list, not in the thesis.
Call under review: HIGH · "Lumentum: The Optics Play That Bridges Power and Memory."
Unchanged from the previous dossier. One amendment: the prior dossier's product map should now read five indium-phosphide fabs, not four — the Greensboro, North Carolina site acquired from Qorvo is explicitly "a fifth indium phosphide fab," currently converting from gallium arsenide, with the transferred workforce included in the purchase and no revenue contribution in current projections ("six or so quarters away").
the previous dossierThe moat description (process + IP in the laser chip; vertical integration; OCS/MEMS; the NVIDIA lock) stands. Two things the new material changes:
No new quarter. The product-type split is unchanged from the prior dossier and is now written to the research layer for the first time (our figures, six rows, three quarters):
| Quarter (calendar) | Components | Systems | Total | Components share |
|---|---|---|---|---|
| 2025-Q3 (FQ1 FY26) | $379.2M (+63.9% YoY) | $154.6M (+46.5%) | $533.8M | 71.0% |
| 2025-Q4 (FQ2 FY26) | $443.7M (+68.3%) | $221.8M (+60.1%) | $665.5M | 66.7% |
| 2026-Q1 (FQ3 FY26) | $533.3M (+77.3%) | $275.1M (+121.1%) | $808.4M | 66.0% |
What the newly-ingested call adds underneath the split: within Components, narrow-linewidth laser assemblies +>120% YoY and pump lasers +80% YoY — the growth is broader than "EMLs into 1.6T," which matters because it means the franchise is not a single-SKU story. Within Systems, cloud transceivers +>40% sequentially, with 1.6T production stepping up in the June quarter at margins "better than 800-gig" but transceiver segment margin overall "still a bit challenged."
This is the honest state: the latest reported quarter is still fiscal Q3 FY26 (ended 2026-03-28), the same quarter the prior dossier analyzed. Nothing in Lens 5's reported figures has changed. What has changed is that the guidance is now written to the research layer and resolves tomorrow.
The bar being cleared tomorrow:
| Metric | Guide low | Guide high | Midpoint | Street |
|---|---|---|---|---|
| Revenue (fiscal Q4 FY26) | $960M | $1,010M | $985M | — |
| Non-GAAP operating margin | 35.0% | 36.0% | 35.5% | — |
| Non-GAAP diluted EPS | $2.85 | $3.05 | $2.95 | $2.97 |
At the guide midpoint, FY2026 revenue = $2,007.7M (nine months, GAAP) + $985M = $2,992.7M, which ties to the street's $2.99B almost exactly. That agreement is worth noting: the sell side is modeling the guide, not above it.
Balance-sheet flags — what to check in the 10-K, and why. As of 2026-03-28 the balance sheet carried $3,238.6M of debt in current liabilities because every convertible series had breached its 130%-of-conversion-price trigger, against $2,617.8M cash and $554.5M short-term investments; total debt $3,281.8M; total equity $2,973.4M. Since that balance-sheet date two equitization events have settled: the April 2026 exchange of ~5.7M shares for portions of the 2026 and 2029 Notes (disclosed as a subsequent event in the Form 10-QThe quarterly version of the annual report. Lighter, and not audited.), and the June 4 exchange of ~5.0M shares for $650.4M of the 2028s. The FY26 balance sheet should therefore show materially lower total debt and a much smaller current-debt reclass. If it does not, that is a flag — it would mean the equitization did not do what the Form 8-KA filing for something that happened between reports and matters enough to tell shareholders now. described.
Four more things to verify in the print, ranked by how much they would move the thesis:
Market reaction, refreshed. The tape's behaviour since June confirms the prior dossier's read that LITE no longer trades on its own print. It fell 5.62% on the day of the fiscal-Q3 beat-and-raise. Since then the moves that mattered were an index reconstitution, an Alphabet capex line, and a Reuters policy leak — none of them Lumentum's own numbers.
The prior dossier ran this lens entirely on second-hand summaries because transcripts/ was empty. It is no longer empty: transcripts/2026-q1.md (the 2026-05-05 fiscal-Q3 FY26 call, Fool transcript, 55.9KB) is on the shelf.
Tone across the last four calls (FQ4 FY25 → FQ3 FY26): escalating, and specifically escalating on scarcity, not on demand. The revenue path is $480.7M → $533.8M → $665.5M → $808.4M → guided ~$985M. But the sentence that defines this call is a supply sentence, not a demand one:
Hurlston: "We are significantly undershipping demand. And we're having to make choices as to who we support." The imbalance is "probably even higher than we reported in our last call, somewhere greater than 30%."
That is a deterioration in the prior call's number (25–30%) presented as good news, and it is the correct way to read it — but it is also a management team publicly admitting it is rationing its own customers. That has a second-order cost the bulls do not price: a rationed customer qualifies a second source.
What is new in the language versus the prior three calls:
the previous dossier (one refreshed data point)The peer table is not re-sourced here. One point worth carrying forward: as of 2026-08-04 the two closest comps traded at COHR TTM P/E ~127.17x and LITE ~128.24x — i.e. the ~8-point premium LITE carried on forward multiples in June has compressed to roughly parity on trailing. LITE's own TTM P/E is quoted at 158.51x by a different aggregator on 2026-08-10. Conflict surfaced, not resolved: the two TTM figures are ~24% apart and I could not reconcile which trailing EPS base each uses. Treat trailing multiples for this name as unusable and work forward.
The prior dossier's three-regime history (2021–22 consolidation, 2023–mid-24 telecom trough, late-2024→mid-2026 AI re-rating) stands. What the last 53 days added is a fourth phase the prior dossier could not see: the first real AI-optics de-rating. Every move below is >5% and dated [all web]:
| Date | Move | Driver |
|---|---|---|
| 2026-05-11 | ATH close $1,053.09 | peak of the AI-optics re-rating [macrotrends] |
| late June 2026 | -11.7% | removal from multiple Russell benchmarks (Russell 2500, Russell 3000 / Midcap Value) at annual reconstitution [Simply Wall St] |
| ~2026-06-25 → early July | ~$887 → ~$698 | continuation; no company-specific news identified [stockstotrade, 2026-07-20] |
| 2026-07-15 | complex sells off (AAOI -12%) | "AI optics trade cools" [247wallst, 2026-07-15] |
| 2026-07-20 | rebound to ~$792 | Citi reiterates Buy, adds 90-day upside catalyst watch; offset by TD Cowen PT $995 → $800, Hold [stockstotrade] |
| 2026-07-28 | -9% to $644.56 | Alphabet Q2 capex $44.92B (2× YoY), FCF -$5.86B, FY26 capital budget $195–205B → investors question AI-capex ROI. COHR -11%, AAOI -10% [247wallst] |
| 2026-07-31 | +5% | risk-on across optics, no company news [247wallst] |
| 2026-08-03 | +9% | first circulation of the Reuters Chinese-transceiver-ban report [247wallst] |
| 2026-08-04 | +6% to $829.42 | confirmation of the draft FCC/administration ban targeting Zhongji Innolight (~27% global transceiver share); draft only, target enforcement by year-end 2026. COHR +11% to $319.80, AAOI +17% to $129.34 [Reuters via 247wallst] |
| 2026-08-10 | $833.78 | drift into the 2026-08-11 print [stockanalysis.com, 11:35 EDT] |
Peak-to-trough: -38.8% in eleven weeks, on a business whose own numbers improved throughout. What the pattern reveals, updated: the marginal buyer is an AI-thematic fund and the marginal seller is now an index rebalance and a hyperscaler capex headline. The prior dossier called this vulnerability; the last 53 days priced it. The one genuinely idiosyncratic driver in the whole window — the Chinese-module draft rule — is worth +15% across two sessions, which is a fair estimate of what a final rule would be worth again, and of what abandoning it would cost.
The prior dossier's read on Hurlston (proven datacom-optics operator, hired-closer profile, ~16 months in — now ~18) is unchanged and unchallenged by anything in this window. Three updates:
The prior dossier's forensic read stands: clean audit (Deloitte, unqualified on FY25 financials and ICFR, single Critical Audit Matter on inventory E&O), a convertible stack as the dominant flag, a ~37% GAAP/non-GAAP wedge driven by SBC and acquired-intangible amortization, an FY25 "profit" that was entirely a $198.0M tax benefit, and one-offs (a $34.9M facility gain in FY25, a $27.5M escrow settlement in FY26) that must be stripped for a clean run-rate. All of that is now encoded in our figures note fields rather than living only in prose.
What changed:
regulatory/regulatory-findings.md was re-fetched on 2026-08-10 covering 2021-08-10 → 2026-08-10 across SEC Litigation Releases and AAERs: total_sec_findings: 0 — no LR, no AAER naming the issuer. The prior dossier's two web-sourced items (the insider-trading ring against a former CISO in which Lumentum was the victim, and a $7.8M export-control settlement charged in fiscal Q2 2023) are unchanged and remain the only "findings." Nothing new surfaced in this window.Model status — read this before any number below. model.xlsx was built for the first time this run (our model, MODEL_VERSION 2.0, 7 quarters 2024-Q3 → 2026-Q1, opening balance sheet sourced from our figures, not hand-typed). Reading it back returns: "No computed values. The workbook has 51 formulas and no cached results." Share price and CAPM inputs are blank; the balance check cannot be read. Therefore no valuation output from the workbook is cited anywhere in this dossier. The workbook is a scaffold on disk awaiting an Excel pass, and every figure below is an explicit `` with the arithmetic shown.
Correction to the prior dossier — two errors, both in the direction of flattery.
Where the multiple actually is, at $833.78:
| Basis | EPS | Multiple |
|---|---|---|
| FY2026 non-GAAP (guide midpoint) | $8.09 | ~103x |
| FY2026 non-GAAP (street) | $8.23 | ~101x |
| FY2027 (street) | $18.73 | ~44.5x |
| Aggregator "forward P/E" (NTM blend) | ~$15.97 implied | 52.2x |
Three-year non-GAAP EPS path — rebuilt on the guided ~102M share base.
Shared arithmetic for every cell: EPS = ((revenue × non-GAAP operating margin) + net other income) × (1 − 15% tax) ÷ diluted shares. Net other income is taken as +$0.08B/yr. Tax at 15%. Diluted shares 104M FY27, 106M FY28.
| Scenario | FY2026 | FY2027 | FY2028 | Logic |
|---|---|---|---|---|
| Bear | $8.09 | ~$12.9 | ~$11.7 | FY27 rev $4.4B (+47% on FY26 but only +12% on the ~$3.94B Q4 exit run-rate — a digestion year) at 34% op margin → (4.4×0.34 + 0.08) × 0.85 ÷ 104 = $12.9. FY28 rev $4.6B at 30% as the ~50.7M-unit/month industry capacity lands and ASPs give back → (4.6×0.30 + 0.08) × 0.85 ÷ 106 = $11.7. |
| Base | $8.09 | ~$17.6 | ~$22.9 | FY27 rev $5.6B (Q4 exit ~$985M/qtr ramping toward management's near-term $1.25B/qtr target; average ~$1.4B/qtr) at 37% → (5.6×0.37 + 0.08) × 0.85 ÷ 104 = $17.6. FY28 rev $7.3B (+30%) at 38% → (7.3×0.38 + 0.08) × 0.85 ÷ 106 = $22.9. |
| Bull | $8.09 | ~$21.6 | ~$28.9 | FY27 rev $6.4B at 40% → (6.4×0.40 + 0.08) × 0.85 ÷ 104 = $21.6. FY28 rev $8.6B at 41% → (8.6×0.41 + 0.08) × 0.85 ÷ 106 = $28.9. |
Two sanity checks on that table. (i) My base FY27 of $17.6 sits just under the street's $18.73 — the sell side is modeling either slightly more revenue or slightly fewer shares; the two are within a rounding error of each other, which is reassuring for the base but means the base case is the consensus case, and consensus is what a 44.5x multiple is already paying for. (ii) The bull case is management's own stated target: $2.0B/quarter at 40% non-GAAP operating margin on an 18–24-month timeline from March 2026 annualizes to $8.0B at 40% → (8.0×0.40 + 0.08) × 0.85 ÷ 106 = $26.3, i.e. 31.7x at today's price. That is the cleanest single frame for this stock: you are paying ~32x for management hitting its own publicly stated 18–24-month plan, and ~103x if it stops here.
Downside arithmetic. A de-rate to 30x on bear FY2028 EPS of $11.7 is ~$351, i.e. -58% from $833.78. The prior dossier's bear landed at ~$380 on different inputs; the two agree that the downside is roughly a halving and is larger than the street's ~32% upside to a $1,105 consensus target. Nothing about the 14% price decline since June has changed that asymmetry — because the earnings base fell about as much as the price did.
No Brier forecast logged — our model create is out of scope for an unattended refresh. The natural one to log, unchanged from the prior dossier and now sharper: "LITE FY27 non-GAAP EPS ≥ $17, resolves ~2027-08-15."
Bull case, updated. The toll-booth thesis is intact and the toll got more expensive to bypass. Lumentum is undershipping demand by >30% and rationing customers; EML units are guided +>50% into December 2026; narrow-linewidth assemblies are +>120% YoY and pump lasers +80%, so this is a franchise, not a SKU; non-GAAP operating margin went 32.2% → guided 35–36% with 40% as the stated destination; OCS sits on a multiyear multibillion-dollar purchase agreement; internal CW lasers hit ~20% of own-transceiver content this quarter with margin upside as it scales; a fifth InP fab is being stood up with none of its capacity in guidance; and management is converting the shortage into take-or-pay, prepayment and price-increase terms — customer-funded capacity, which is how a cyclical hardware business becomes a contracted one. On top of that, Washington is drafting a rule that would remove a ~27%-share Chinese competitor from the US market. Meanwhile the price is 21% below its May high and the FY27–28 multiple has compressed.
Bear case (permanent-impairment lens), updated.
Pre-mortem (18 months out, thesis broke — what happened?). The Chinese-transceiver rule was quietly abandoned in Q4 2026 after hyperscaler lobbying over input costs, removing the August catalyst and returning Innolight to the US market. Hyperscaler capex growth flattened in CY2027 as the -$5.86B FCF quarters that spooked the tape in July 2026 turned into board-level discipline. The >30% supply gap closed — not because Lumentum failed to add capacity, but because the industry added ~2x monthly EML/CW-DFB units and Coherent's larger-wafer platform undercut on price; ASPs fell, gross margin slipped from ~48% toward ~40%, and the take-or-pay terms Lumentum negotiated at the peak of scarcity became the thing customers renegotiated. NVIDIA, having secured its capacity, dual-sourced the next node. Greensboro's capacity arrived into a softer market. Diluted shares reached ~106M. FY28 EPS came in near $12 instead of $23, the multiple went to 30x, and the stock printed ~$350 — down 58% — with the business still fine and still the leader.
Are multiples too high? At ~103x the closing year, yes unambiguously. At ~32x management's own 18–24-month target, no. The whole question is which of those two numbers is the right denominator, and the answer arrives in installments starting tomorrow.
Contrarian view — updated, and it has moved. The prior dossier's contrarian read was "the NVIDIA $2B is as much a leash as a gift." That still holds, and the newly-ingested call extends it: management is now negotiating take-or-pay and prepayment terms with multiple key customers to fund capacity. Read one way that is contracted revenue. Read the other way, Lumentum is selling forward the exact scarcity that is producing today's 48% gross margin — locking in price and volume at the moment its bargaining power is at a cyclical maximum, with the counterparties being the largest buyers on earth. The market is scoring these agreements as pure de-risking. They are also a ceiling, negotiated by the party with more lawyers.
Dismantling the bull case with what the last 53 days actually produced.
the previous dossierAll fifteen questions stand. Question #10 (the plan for the 2028 Notes) has been answered by events — $650.4M equitized on 2026-06-04, ~$172.2M stub remaining. Question #6 (the fully-diluted share count management is managing to) has been partially answered: ~102M. Two questions to add for the 2026-08-11 call:
Every dossier we have written on Lumentum, newest first, including where a later one corrected an earlier one.
The operating story got better and the stock got cheaper
CorrectionForward Projection — rebuilt, with a correction to the prior dossier Model status — read this before any number below. model.xlsx was built for the first time this run (our model, MODELVERSION 2.0, 7 quarters 2024-Q3 →…
The arms-dealer of the AI optics build-out
Covered in the Knowledge Base
Networking & Interconnect
| Industry | Optical Computing |
| Size | Public Company |
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