Lam Research Q1 FY2027: The $8.22B Quarter That Turned Shipments Into Cash

Lam Research guided $8.10 billion for the September quarter and printed $8.22 billion — up 54% year over year, with record revenue, profit and earnings per share — and then answered the one question its record FY2026 left open: operating cash flow of $3.50 billion, 127% of net income, as days-sales-outstanding fell from 72 to 63 days in a single quarter. The growth is no longer on credit. Every figure below is asserted line by line in the public Beancount ledger embedded at the end of this post.

The Headline Numbers​

Lam's fiscal Q1 is the thirteen weeks ended September 27, 2026. Every figure below comes from the Form 8-K and its earnings release exhibit; March-quarter comparatives are from the June-quarter release. Lam reports in thousands, and the ledger keeps all three decimals.

Read top to bottom and this is operating leverage in its purest form: revenue grew 54% while cost of goods sold grew 48% and operating expenses grew 19%, so 560 basis points of operating margin fell out almost arithmetically. Sequentially the quarter is just as loud — revenue +22.3% and operating income +30.6% on the June quarter, the second straight quarter of 20%-plus sequential growth. The one line growing faster than revenue is the tax bill at +92%, as the effective rate jumped to 16.9% — the only real drag on a print where net income still compounded well ahead of sales. GAAP and non-GAAP barely differ this quarter ($2.19 vs $2.20 diluted EPS), so there is no adjustments story to untangle; the adjustments are a rounding error on a quarter this profitable.

Revenue Deep Dive​

Lam splits revenue into systems (new leading-edge tools) and customer support (spares, services, upgrades, Reliant tools), and this quarter the two lines told very different stories:

Systems did the accelerating: +62% year over year and +35% sequentially, adding $1.48 billion in ninety days. That is new deposition, etch and clean tools shipping into fab expansions — the AI-capex line in its purest form, and the ledger's single Income:Revenue posting carries the split in its comment because the filing's total is what the books assert. Support grew a thumping 40% year over year but essentially flatlined sequentially (+0.6%), which is the number to watch next quarter: a support business that stalls while systems surge can mean the installed base is digesting, or just a lumpy spares quarter. One flat quarter after years of compounding is noise until it repeats.

Geographically the map is stable at the top and therefore stable in its risk: China 35%, Korea 20%, Taiwan 18%, Japan 9%, the United States 8%, Southeast Asia 6%, Europe 4%. China ticked up a point to more than a third of revenue for the third distribution running — the number the Bear Case below is built on, since every export-control headline lands directly on this line. The release's own risk list names trade regulations, export controls and geopolitical tensions as threats to the outlook it just raised.

Management signal scan (October 21 earnings release):

• Robust demand: "With AI driving higher semiconductor demand and greater device complexity, our focus on operational execution helped Lam deliver record revenue, profit, and earnings per share in the September quarter" (CEO Tim Archer, release). The ledger confirms the demand half — systems +62% — and the execution half: gross margin expanded 60 bps sequentially while shipping 35% more tools, which does not happen by accident.
• Outperformance framing: "Our strategic investments in technology inflections and manufacturing capacity are paying off, strengthening our ability to outgrow the wafer fabrication equipment market as the industry expands" (Archer, release). "Outgrow the market as the industry expands" is an upcycle claim wrapped in a market-share claim — Lam is saying the pie is growing and its slice is widening. The second straight 20%-plus sequential quarter is the evidence offered.
• Guidance as a demand signal: revenue of "$8.60 Billion +/- $400 Million" for the December quarter (release). The midpoint is only 4.6% above the record just printed — a sharp deceleration from +22% — which is either conservatism after two beats or the first honest signal that the acceleration is topping. That question gets its own section below.
• Absence as a finding: there is still no "demand exceeds supply" language, no tight-supply or lead-time claim, no pricing-momentum language, and no product-ramp boast anywhere in the release. For a company printing 40% operating margins, the silence on price is conspicuous — Lam is attributing its best quarter ever to mix and execution, not to charging more. And "backlog" never appears; the closest proxy, deferred revenue, rose 9.5% sequentially to $2.66 billion, which the release states as fact rather than framing as momentum. The bullishness remains all in the numbers and the guide, not the adjectives.

The Margin Story​

Four quarters of margins show expansion on every line for three straight quarters — with one new headwind:

The gross-margin mechanics are volume leverage, mechanically visible: cost of goods sold grew 48.5% against revenue's 54.4%, and the 190 bps of year-over-year expansion came with systems — the mix the FY2026 10-K credits for "favorable customer mix" — growing fastest. Below gross profit, the opex story is restraint verging on the remarkable: R&D grew just 15.6% year over year and 3.7% sequentially while revenue grew 54% and 22% on the same bases. Lam spent $666 million on R&D — 8.1% of revenue, down from 10.8% a year ago — while expanding operating margin 560 bps. That ratio cannot fall forever without the innovation pipeline noticing, but in a capacity race it is exactly the right trade: ship tools now, staff later. SG&A at 4.2% of revenue remains almost comically lean for a company running at a $33 billion annualized pace.

Then the net-margin bridge hits the tax wall. The effective rate jumped from 10.9% in June to 16.9% — tax expense more than doubled quarter over quarter to $559 million, including an $11.5 million charge from a change in tax law that the release carves out of non-GAAP results. That is why net margin fell 40 bps sequentially while operating margin rose 260 bps: Lam kept 40 cents of every revenue dollar before the tax line and gave back a growing share after it. At the June rate, net income would have printed roughly $195 million higher and diluted EPS around $2.35. Taxes, not operations, are now the binding constraint on earnings growth — and the December guide's EPS midpoint of $2.33 assumes the higher rate persists.

The One Big Question: Is +4.6% December Growth the Top of the Acceleration?​

Lam beat its own September guide — $8.219 billion actual against an $8.10 billion midpoint, +1.5%, comfortably inside the ±$400 million band — and then guided December to $8.60 billion at the midpoint. That is 4.6% sequential growth after two quarters of 15% and 22%. Three checks decide whether the deceleration matters.

Check one: the guide math. Annualize the first half of FY2027 at the midpoints — $8.22 billion plus $8.60 billion — and Lam is already at $16.8 billion with two quarters unreported. Even flat second-half quarters would put FY2027 at $33.6 billion, 45% above FY2026's record $23.2 billion. A "slowdown" to +4.6% sequential is still a full year growing nearly twice as fast as last year's 26%. The deceleration is from sprint to run, not from run to walk — and the band's top end ($9.0 billion) would be a ninth straight record category of quarter. Lam has now beaten two consecutive guide midpoints; the December midpoint deserves the benefit of the doubt until it misses one.

Check two: the margin guide is still expanding. December's 52.5% gross margin and 40.5% operating margin midpoints are each up on September's 52.3% and 40.0%. Companies topping out do not guide margins up — mix deterioration shows up in gross margin first, and Lam is explicitly forecasting the opposite. The $2.33 EPS midpoint (+6.4% sequentially on a 1.253-billion share count) bakes in the higher tax rate, so any tax normalization is pure upside to the print.

Check three: the backlog proxy is confirming, not warning. Deferred revenue rose from $2.43 billion to $2.66 billion within the quarter (+9.5%), and another $468 million of Japan shipments sits in inventory awaiting customer acceptance. The FY2026 post flagged deferred profit's annual drawdown as the line to watch and said a second quarterly rebuild would make it a trend — this is that second rebuild. Lam is accumulating future revenue while shipping records, the opposite of eating its seed corn. Add receivables growing just 6.0% against revenue's 22.3% — DSO falling from 72 to 63 days — and the balance sheet is describing a company whose customers pay faster as they buy more. Verdict: the +4.6% is pacing, not peaking. Revisit if deferred revenue stalls while the guide keeps decelerating.

Tracking a $33 Billion Company in Plain Text​

A company running at a $33 billion annualized pace fits in a plain-text ledger because double-entry bookkeeping forces every dollar to reconcile — revenue minus every expense must equal net income to the thousand dollars, or the file refuses to balance. That discipline is the point: this post's tables are not screenshots of a spreadsheet but assertions a computer re-verifies. Lam's chart of accounts is modeled on how we model every company, with the equipment-maker shape it shares with Applied Materials — an explicit Inventories line, and Lam's "Deferred profit" caption mapped to DeferredRevenue. Condensed quarters assert the release's aggregated lines exactly as printed — the single-line equity total sits on Equity:UndisaggregatedParent with the components at zero, never estimated — and the FY2027 10-K will restore the split.

Here is Q1 FY2027's income statement exactly as the ledger records it (income is negative because it is a credit; the check comment above the transaction proves the postings sum to zero):

; INCOME STATEMENT — first quarter, three months ended September 27, 2026
; Check: −8219.418 + 3920.565 + 666.398 + 348.728 − 28.493 + 559.082 + 2753.138 = 0 ✓
 
2026-09-27 * "Lam Research Corporation" "FY2027Q1 Income Statement"
  Income:Revenue                           -8219.418 MUSD  ; systems 5732.907 + customer support-related revenue and other 2486.511
  Expenses:CostOfRevenue                    3920.565 MUSD
  Expenses:ResearchAndDevelopment            666.398 MUSD
  Expenses:SellingGeneralAdministrative      348.728 MUSD
  Income:OtherNet                            -28.493 MUSD  ; other income, net
  Expenses:IncomeTax                         559.082 MUSD
  Equity:Adjustments                         2753.138 MUSD  ; reported net income offset

The balance-sheet number that tells the Q1 narrative is cash: $5.58 billion to $7.44 billion in ninety days, as $3.50 billion of operating cash flow dwarfed $1.02 billion of buybacks, $325 million of dividends and $258 million of capex combined. Net cash roughly doubled to $3.70 billion — Lam returned $1.35 billion to shareholders and still got richer by nearly $2 billion in a quarter. Browse all six periods below:

The Multi-Year Arc​

Five years of the ledger compress the semiconductor cycle into one table: the FY2024 trough, when revenue fell 14%, followed by two years of 23.7% and 26.0% growth — and now a quarter annualizing to $32.9 billion, 42% above the FY2026 record pace.

Three things stand out. First, the margin structure has ratcheted, not cycled: September's 52.3% gross and 40.0% operating margins are roughly seven and nine points above the FY2024 trough, and each of the last three quarters set a new high on both lines. This is mix permanence — foundry tools at 54%-plus of the mix — until proven otherwise. Second, the cash doubt is resolved, decisively: Q1's $3.50 billion of operating cash flow is 60% of all of FY2026's full-year total in a single quarter, at 127% conversion of net income, with DSO at 63 days — its best reading since the supercycle began. The FY2026 post said FY2027 had to prove conversion; one quarter in, it has. Third, per-share compounding keeps quietly outperforming: the diluted share count is flat to down even as equity compensation grows, because $1.02 billion quarterly buybacks now offset dilution and then some — which is why EPS grew 76.6% against net income's 75.5%. The arc says this company converts eventually. It just did, ahead of schedule.

The Verdict: Bull vs. Bear​

Bull Case

• The cash question is answered. $3.50 billion of operating cash flow at 127% of net income, DSO down nine days to 63, receivables growing a third the pace of revenue — the FY2026 balance-sheet doubt resolved in one quarter.
• Two straight 20%-plus sequential quarters. +15%, then +22.3%, with December guided to $8.60 billion — first-half FY2027 already annualizes past $33 billion, 42% above FY2026's record.
• Margins still expanding into the guide. September's 40.0% operating margin is a record, and December guides up to 40.5% — mix deterioration would show in gross margin first, and Lam forecasts the opposite.
• Systems +62% is pure AI capex. $5.73 billion of new leading-edge tools at nearly double the growth rate of the already-strong support line — every new fab bay still needs Lam before shipping a wafer.
• Capital return with a doubling cash pile. $1.35 billion returned (39% of operating cash flow) while net cash doubled to $3.70 billion and the dividend rose 27% to $0.33 — the balance sheet funds growth, buybacks and payout hikes simultaneously.

Bear Case

• China is 35% of revenue and rising. More than a third of sales into the jurisdiction every export-control headline targets, up a point this quarter; the release's own risk list names trade regulations and export controls as threats to the raised outlook.
• The tax rate is the new headwind. 16.9% vs 10.9% last quarter — tax expense doubled sequentially and shaved 40 bps off net margin while operating margin rose 260 bps. At the old rate, EPS prints $2.35, not $2.19.
• Support revenue flatlined sequentially. +0.6% after years of compounding, while systems surged 35% — if the installed base is digesting rather than pausing, the "floor" thesis cracks.
• +4.6% December growth prices perfection differently. The guide deceleration is honest, but a $8.60 billion midpoint with ±$400 million bands means any slip — a delayed fab, a pushed acceptance — misses loudly against a stock priced for beats.
• The cycle always collects. FY2024 was barely two years ago: revenue down 14%, trough margins. Equipment orders lead wafer demand by quarters, and today's foundry concentration means Lam's customers cut deepest exactly when memory turns.

Our Take: Believe the acceleration but re-underwrite the price of admission. Lam just produced the quarter its FY2026 post demanded — record everything plus cash conversion at 127% — and the December guide's margin expansion says the mix story has at least another quarter to run. But the easy part of this trade, buying doubts about receivables, is over: what remains is a 35%-China, tax-dragged compounder guiding single-digit sequential growth at peak margins. The ledger's next entries — deferred revenue's third rebuild, support revenue's re-acceleration, the tax rate's direction — decide whether FY2027 is a $34 billion year or a $38 billion one. Either is a record. The difference is the multiple.