⚠ The Worst Month in KLA's HistoryModerate threat

KLA (KLAC) — threat to the moat

KLA's shares fell more than 40% in July 2026 without any change in the business, and they still trade at 51 times trailing earnings.

In July 2026 the market decided KLA's shares had run too far, and the fall was the worst in the company's history. Barron's reported that the stock "has fallen over 40% this month, marking its worst performance in history", citing Dow Jones Market Data1. The fall began before the results: on 2 July the shares closed at $235.55, down 11.51% in a day, after short interest rose more than 1,000% in late June to about 40.8 million shares, according to TIKR2.

KLA market value ($bn)118.530 Jun 2025159.731 Dec 2025394.130 Jun 2026245.225 Sep 2026stockanalysis ratios and market-cap history; market data, 25 September 2026
Up 3.3 times in a year, then down 38%.

The business did not change in July. The fourth-quarter report on 28 July showed record revenue of $3,657.6 million and guided the next quarter to $4.0 billion3; the shares still sank 8.9% after it4. Susquehanna said it sees limited opportunity for KLA's systems business to outpace the equipment market, as Barron's reported5.

The price had been extreme. At the fiscal year-end on 30 June the market value was $394.1 billion, 81.58 times earnings6. On 25 September the shares closed at $187.92, a market value of $245.24 billion7, and the 52-week range was $98.10 to $307.378.

After the fall the shares are still not cheap. They trade at 51.3 times trailing and 34.45 times forward earnings9, which assumes the growth analysts expect.

The collapse gathered speed through the month. An early edition of Barron's report on 29 July said the shares had shed nearly 38% month to date and slid 5.7% after the report10; the later edition put the fall above 40% and the post-report drop at 8.9%11. Stockanalysis showed short interest at about 23.55 million shares, 1.80% of the total, in September12, well below the late-June peak TIKR reported13.

The fall is a warning about valuation, not the business. It becomes a warning about the business if revenue in the September quarter comes in below the $3.8 billion bottom of the guidance14; the gap from the 52-week high, 38.9% in September15, is the market's running verdict.

The number that tests this threat
Moat Explorer calc
Share price below 52-week high
38.9% (25 Sep 2026: $187.92 against $307.37)

The market's running verdict; a record quarter that failed to narrow the gap would say the multiple still had further to fall.

How it's calculated: Closing price on 25 September 2026 divided by the 52-week high, stockanalysis, less one.
Source: Moat Explorer calculation from KLA filings ↗
References
  1. ReportedBarron's reported that the stock "has fallen over 40% this month, marking its worst performance in history", citing Dow Jones Market Data.
    Barron's via Bitget - KLA shares sank 8.9% after the fourth-quarter report and had fallen over 40% in July 2026, the worst month in the stock's history according to Dow Jones Market Data; analysts' estimates for the September quarter; a Susquehanna view on systems growth. — July 2026 · publ. 29 July 2026 · source ↗
  2. ReportedThe fall began before the results: on 2 July the shares closed at $235.55, down 11.51% in a day, after short interest rose more than 1,000% in late June to about 40.8 million shares, according to TIKR.
    TIKR - KLA closed 2 July 2026 at $235.55, down 11.51% on the day; short interest rose more than 1,000% in late June to about 40.8 million shares. — July 2026 · publ. July 2026 · source ↗
  3. ReportedThe fourth-quarter report on 28 July showed record revenue of $3,657.6 million and guided the next quarter to $4.0 billion; the shares still sank 8.9% after it.
    KLA fourth-quarter fiscal 2026 results release, Form 8-K exhibit 99.1 - revenue, product and service revenue, segment revenue, net income, cash flow, capital returns and September 2026 quarter guidance. — Q4 FY2026 · publ. 28 July 2026 · source ↗
  4. ReportedThe fourth-quarter report on 28 July showed record revenue of $3,657.6 million and guided the next quarter to $4.0 billion; the shares still sank 8.9% after it.
    Barron's via Bitget - KLA shares sank 8.9% after the fourth-quarter report and had fallen over 40% in July 2026, the worst month in the stock's history according to Dow Jones Market Data; analysts' estimates for the September quarter; a Susquehanna view on systems growth. — July 2026 · publ. 29 July 2026 · source ↗
  5. ReportedSusquehanna said it sees limited opportunity for KLA's systems business to outpace the equipment market, as Barron's reported.
    Barron's via Bitget - KLA shares sank 8.9% after the fourth-quarter report and had fallen over 40% in July 2026, the worst month in the stock's history according to Dow Jones Market Data; analysts' estimates for the September quarter; a Susquehanna view on systems growth. — July 2026 · publ. 29 July 2026 · source ↗
  6. ReportedAt the fiscal year-end on 30 June the market value was $394.1 billion, 81.58 times earnings.
    KLA ratios by fiscal year - market capitalisation, P/E and P/S at fiscal year-ends 2022-2026 (FY2026: $394,116M, 81.58 times earnings, last close $301.37). — FY2022-FY2026 · publ. September 2026 · source ↗
  7. ReportedOn 25 September the shares closed at $187.92, a market value of $245.24 billion, and the 52-week range was $98.10 to $307.37.
    KLA (KLAC) market data - $187.92 a share at the close on 25 September 2026, market cap $245.24B, trailing P/E 51.34, forward P/E 34.45, 52-week range 98.10-307.37, dividend $0.92 (0.49%), 29 analysts with a price target of $233.77, estimated earnings date 28 October 2026. — September 2026 · publ. 25 September 2026 · source ↗
  8. ReportedOn 25 September the shares closed at $187.92, a market value of $245.24 billion, and the 52-week range was $98.10 to $307.37.
    KLA (KLAC) market data - $187.92 a share at the close on 25 September 2026, market cap $245.24B, trailing P/E 51.34, forward P/E 34.45, 52-week range 98.10-307.37, dividend $0.92 (0.49%), 29 analysts with a price target of $233.77, estimated earnings date 28 October 2026. — September 2026 · publ. 25 September 2026 · source ↗
  9. ReportedThey trade at 51.3 times trailing and 34.45 times forward earnings, which assumes the growth analysts expect.
    KLA (KLAC) market data - $187.92 a share at the close on 25 September 2026, market cap $245.24B, trailing P/E 51.34, forward P/E 34.45, 52-week range 98.10-307.37, dividend $0.92 (0.49%), 29 analysts with a price target of $233.77, estimated earnings date 28 October 2026. — September 2026 · publ. 25 September 2026 · source ↗
  10. ReportedAn early edition of Barron's report on 29 July said the shares had shed nearly 38% month to date and slid 5.7% after the report; the later edition put the fall above 40% and the post-report drop at 8.9%.
    Barron's via Bitget - KLA shares slid after the fourth-quarter report and had shed nearly 38% month to date in July 2026. — July 2026 · publ. 29 July 2026 · source ↗
  11. ReportedAn early edition of Barron's report on 29 July said the shares had shed nearly 38% month to date and slid 5.7% after the report; the later edition put the fall above 40% and the post-report drop at 8.9%.
    Barron's via Bitget - KLA shares sank 8.9% after the fourth-quarter report and had fallen over 40% in July 2026, the worst month in the stock's history according to Dow Jones Market Data; analysts' estimates for the September quarter; a Susquehanna view on systems growth. — July 2026 · publ. 29 July 2026 · source ↗
  12. ReportedStockanalysis showed short interest at about 23.55 million shares, 1.80% of the total, in September, well below the late-June peak TIKR reported.
    KLA (KLAC) statistics - return on equity 87.50%, return on invested capital 66.75%, effective tax rate 13.83%, operating margin 41.69%, FCF margin 27.74%, short interest 23.55 million shares (1.80%). — September 2026 · publ. 25 September 2026 · source ↗
  13. ReportedStockanalysis showed short interest at about 23.55 million shares, 1.80% of the total, in September, well below the late-June peak TIKR reported.
    TIKR - KLA closed 2 July 2026 at $235.55, down 11.51% on the day; short interest rose more than 1,000% in late June to about 40.8 million shares. — July 2026 · publ. July 2026 · source ↗
  14. ReportedIt becomes a warning about the business if revenue in the September quarter comes in below the $3.8 billion bottom of the guidance; the gap from the 52-week high, 38.9% in September, is the market's running verdict.
    KLA fourth-quarter fiscal 2026 results release, Form 8-K exhibit 99.1 - revenue, product and service revenue, segment revenue, net income, cash flow, capital returns and September 2026 quarter guidance. — Q4 FY2026 · publ. 28 July 2026 · source ↗
  15. Moat Explorer calcIt becomes a warning about the business if revenue in the September quarter comes in below the $3.8 billion bottom of the guidance; the gap from the 52-week high, 38.9% in September, is the market's running verdict.
    Moat Explorer calculation from KLA's reported figures ($ millions unless stated; fiscal years end on 30 June; per-share figures adjusted for the ten-for-one split of June 2026). Revenue growth: FY2022 9,211.9 / 6,918.7 - 1 = +33.1%; FY2023 10,496.1 / 9,211.9 - 1 = +13.9%; FY2024 9,812.2 / 10,496.1 - 1 = -6.5%, the only decline FY2015-FY2026; FY2025 12,156.2 / 9,812.2 - 1 = +23.9%; FY2026 13,579.5 / 12,156.2 - 1 = +11.7%; FY2015-FY2026 13,579.5 / 2,814.0 = 4.8 times, 15.4% a year; FY2026 against FY2023 13,579.5 / 10,496.1 - 1 = +29%. Net income FY2024 2,761.9 / 3,387.3 - 1 = -18.5%, a fall of 625.4, of which the 289.5 impairment is 46%; net margin 4,830.8 / 13,579.5 = 35.6%; Other FY2023 381.1 / 259.4 - 1 = +46.9%; gross margin 1,598.8 / 2,814.0 = 56.8% (FY2015), 2,699.5 / 4,568.9 = 59.1% (FY2019); FY2026 4,830.8 / 4,061.6 - 1 = +18.9%; FY2015-FY2026 4,830.8 / 366.2 = 13.2 times; EPS 3.66 / 0.224 = 16.3 times. Operating income (no line reported): gross profit 8,324.4 - R&D 1,532.1 - SG&A 1,131.5 = 5,660.8 (FY2026), 5,660.8 / 13,579.5 = 41.7%; interest cover 5,660.8 / 284.4 = about 20 times. Segments FY2026: Semiconductor Process Control 12,244.7 / 13,579.5 = 90.2% of revenue; segment gross profit 12,244.7 - 4,453.6 = 7,791.1, 7,791.1 / 12,244.7 = 63.6%; segment profit 5,482.8 / 12,244.7 = 44.8%; 5,482.8 / 5,655.4 = 96.9% of segment profit; Specialty Semiconductor Process 64.6 / 584.1 = 11.1%, gross 278.8 / 584.1 = 47.7% (FY2021 206.7 / 369.2 = 56.0%); PCB and Component Inspection 108.0 / 750.4 = 14.4%, gross 385.3 / 750.4 = 51.3% (FY2024 159.0 / 552.5 = 28.8%); smaller segments 64.6 + 108.0 = 172.6; SSP segment gross margin FY2022 242.5 / 456.6 = 53.1%, FY2023 281.9 / 543.4 = 51.9%, FY2024 282.9 / 528.7 = 53.5%, FY2025 303.9 / 587.1 = 51.8%; Orbotech segments revenue less product categories 1,334.5 - (502.5 + 460.3) = 371.7; process control share of research 1,341.3 / 1,532.1 = 87.5%, almost nine-tenths; SG&A 1,131.5 / 13,579.5 = 8.3%; segment revenue 584.1 + 750.4 = 1,334.5. Process control segment research 1,341.3 / 12,244.7 = 11%; segment revenue growth 12,244.7 / 10,947.4 - 1 = +11.9%; SSP products 502.5 / 584.1 = 86% of segment revenue, research 59.4 / 584.1 = 10%; PCI Q4 241.1 / 750.4 = 32% of the year; process control lines FY2019 (1,630.9 + 1,161.3) / 4,568.9 = 61.1%; patterning within process control lines 2,791.1 / (4,336.7 + 2,791.1) = 39.2% (FY2023), 2,706.8 / (6,630.8 + 2,706.8) = 29.0% (FY2026); services share FY2019 1,176.7 / 4,568.9 = 25.8%; capital spending 375.9 / 45.8 = 8.2 times; peers 656.33 + 393.13 + 383.87 = 1,433.3, 1,433.3 / 245.24 = 5.8 times; FY2015 customers 15 + 12 + 11 = 38%. Process control segment gross margin FY2018 2,554.2 / 3,944.0 = 64.8%; FY2019 2,590.4 / 4,080.8 = 63.5%; FY2020 3,028.2 / 4,745.4 = 63.8%; FY2021 3,705.2 / 5,734.8 = 64.6%; FY2022 5,167.7 / 7,924.8 = 65.2%; FY2023 5,957.6 / 9,324.2 = 63.9%; FY2024 5,629.3 / 8,733.6 = 64.5%; FY2025 7,024.6 / 10,947.4 = 64.2%. Process control revenue FY2024 8,733.6 / 9,324.2 - 1 = -6.3%. Orbotech-related goodwill impairments 256.6 + 289.5 + 239.1 = 785.2. Research: 1,532.1 / 530.6 = 2.9 times; 530.6 / 2,814.0 = 18.9% (FY2015); 526.7 / 3,480.0 = 15.1% (FY2017); 711.0 / 4,568.9 = 15.6% (FY2019); 928.5 / 6,918.7 = 13.4% (FY2021); 1,296.7 / 10,496.1 = 12.4% (FY2023); 1,279.0 / 9,812.2 = 13.0% (FY2024); 1,532.1 / 13,579.5 = 11.3% (FY2026); FY2016 481.3 against 530.6 and FY2024 1,279.0 / 1,296.7 - 1 = -1.4%; research staff 27% x 17,000 = about 4,600. Product categories (FY2019-FY2026): wafer inspection 6,630.8 / 1,630.9 = 4.1 times, 22.2% a year; FY2025 6,198.8 / 4,333.3 - 1 = +43.1%; FY2026 6,630.8 / 6,198.8 - 1 = +7.0%; share 1,630.9 / 4,568.9 = 35.7% (FY2019), 6,198.8 / 12,156.2 = 51.0% (FY2025), 6,630.8 / 13,579.5 = 48.8% (FY2026). Patterning 2,706.8 / 1,161.3 = 2.3 times, 12.9% a year; FY2022 2,050.0 / 1,506.0 - 1 = +36.1%; FY2023 2,791.1 / 2,050.0 - 1 = +36.2%; FY2024 2,054.4 / 2,791.1 - 1 = -26.4%; FY2025 2,196.3 / 2,054.4 - 1 = +6.9%; FY2026 2,706.8 / 2,196.3 - 1 = +23.2%; share 2,791.1 / 10,496.1 = 26.6% (FY2023), 2,196.3 / 12,156.2 = 18.1% (FY2025), 2,706.8 / 13,579.5 = 19.9% (FY2026); process control lines 48.8 + 19.9 = 68.7%. SSP products 502.5 / 13,579.5 = 3.7%. PCI products 460.3 / 13,579.5 = 3.4%; FY2025 355.9 / 291.2 - 1 = +22.2%; FY2026 460.3 / 355.9 - 1 = +29.3%. Services 3,125.9 / 1,176.7 = 2.7 times, (3,125.9 / 1,176.7) ^ (1/7) - 1 = 15.0% a year; growth FY2020 +25.6%, FY2021 +13.6%, FY2022 +13.8%, FY2023 +10.8%, FY2024 2,329.6 / 2,117.0 - 1 = +10.0%, FY2025 +15.2%, FY2026 3,125.9 / 2,683.3 - 1 = +16.5%; FY2024 increase 2,329.6 - 2,117.0 = 212.6; share 2,117.0 / 10,496.1 = 20.2% (FY2023), 2,329.6 / 9,812.2 = 23.7% (FY2024), 3,125.9 / 13,579.5 = 23.0% (FY2026). Product revenue FY2023 10,496.1 - 2,117.0 = 8,379.1; FY2024 fall 8,379.1 - 7,482.7 = 896.4. A one-third fall in product revenue 10,453.5 / 3 = 3,484.5 against a year of 15% service growth 3,125.9 x 0.15 = 469, less than a seventh. Other 153.1 / 381.1 - 1 = -60%; 153.1 / 13,579.5 = 1.1%; FY2024 333.2 / 381.1 - 1 = -12.6%; FY2025 204.6 / 333.2 - 1 = -38.6%; FY2026 153.1 / 204.6 - 1 = -25.2%. Deferred system and service revenue 932.9 + 604.1 + 238.1 = 1,775.1, about $1.8 billion. Unrecognised contract price 1,775.1 / 3,125.9 x 12 = about 7 months of service revenue. Region: Taiwan FY2024 1,738.1 / 2,493.4 - 1 = -30.3%; FY2026 against FY2024 3,643.7 / 1,738.1 - 1 = +110%; FY2025 3,205.4 / 1,738.1 - 1 = +84.4%; FY2023 2,493.4 / 2,528.5 - 1 = -1.4%. Korea FY2019 584.1 / 1,178.6 - 1 = -50%; FY2024 906.9 / 1,895.7 - 1 = -52%; share 1,178.6 / 4,036.7 = 29.2% (FY2018), 584.1 / 4,568.9 = 12.8% (FY2019), 1,895.7 / 10,496.1 = 18.1% (FY2023), 906.9 / 9,812.2 = 9.2% (FY2024), 1,833.8 / 13,579.5 = 13.5% (FY2026). China FY2025 4,042.6 / 4,196.7 - 1 = -3.7%; FY2026 4,048.4 / 4,042.6 - 1 = +0.1%; China plus Taiwan 29.8% + 26.8% = 56.6%; Q4 FY2026 China 4,048.4 - 3,091.6 = 956.7, 956.7 / 3,657.6 = 26.2%. Backlog 12,570 / 7,860 - 1 = +59.9%; 12,570 / 13,579.5 = 93% of revenue; unrecognised contract price 1,775.1 / 12,570 = 14% of backlog. Advanced packaging about 1,000 / 13,579.5 = about 7% of revenue. Quarter: Q4 FY2026 revenue 3,657.6 / 3,174.7 - 1 = +15.2%; 3,657.6 / 3,415.1 - 1 = +7.1%; service 820.4 / 702.6 - 1 = +16.8%; process control 3,256.8 / 2,877.6 - 1 = +13.2%; PCB and Component Inspection 241.1 / 154.1 - 1 = +56.5%; GAAP gross margin (3,657.6 - 1,413.1) / 3,657.6 = 61.4%. Guidance midpoint 4,000 / 3,209.7 - 1 = +24.6%; 4,000 / 3,657.6 - 1 = +9.4%. Consensus fiscal 2027 18,110 / 13,579.5 - 1 = +33.4%; EPS 5.45 / 3.66 - 1 = +49%. The 2030 model at 13% a year: 13,579.5 x 1.13 ^ 2 = 17,340 (FY2028); 13,579.5 x 1.13 ^ 5 = about 25,000 (FY2031). Cash and capital: free cash flow 4,143.1 - 375.9 = 3,767.1; capital returns 2,289.8 + 1,057.8 = 3,347.6, 3,347.6 / 3,767.1 = 88.9%; dividends 1,057.8 / 4,830.8 = 21.9% of net income; buybacks 2,289.8 / 1,057.8 = 2.2 times dividends; capital spending 375.9 / 13,579.5 = 2.8% of revenue; operating cash flow 3,308.6 / 2,761.9 = 120% (FY2024), 4,081.9 / 4,061.6 = 100% (FY2025), 4,143.1 / 4,830.8 = 86% (FY2026); operating cash flow growth 4,143.1 / 4,081.9 - 1 = +1.5%; net income less operating cash flow 4,830.8 - 4,143.1 = 687.7; receivables 2,889.2 / 2,263.9 - 1 = +27.6%, an increase of 625.3; inventories 3,648.5 - 3,212.1 = 436.4; together 1,061.7. FY2015 dividends paid 3,041.1 / 366.2 = 8.3 times net income. Buybacks FY2015-FY2026 602.9 + 181.7 + 25.0 + 203.2 + 1,095.2 + 829.1 + 938.6 + 3,967.8 + 1,311.9 + 1,735.7 + 2,149.9 + 2,289.8 = 15,330.8; dividends paid 3,041.1 + 346.3 + 344.0 + 402.1 + 472.3 + 522.4 + 559.4 + 638.5 + 732.6 + 773.0 + 904.6 + 1,057.8 = 9,794.1. Diluted shares 1,319.6 / 1,637.0 - 1 = -19.4%. Net debt 5,887.4 - 1,649.8 - 3,252.6 = 985.0 (FY2026); 5,884.3 - 2,078.9 - 2,415.7 = 1,389.7 (FY2025); 6,630.1 - 1,977.1 - 2,526.9 = 2,126.1 (FY2024); 985.0 / 3,767.1 = 26% of free cash flow. Return on equity 4,830.8 / ((4,692.5 + 6,349.8) / 2 = 5,521.2) = 87.5%; FY2025 4,061.6 / ((3,368.3 + 4,692.5) / 2) = 100.8%; FY2024 2,761.9 / ((2,919.8 + 3,368.3) / 2) = 87.9%. Buyback authorisation 9,740 / 245,240 = 4%; 9,740 / (0.9 x 3,767.1) = 2.9 years; 9,740 / 571.0 = 17 quarters. Valuation: market value 245,240 / 383,870 = 0.64 (Applied Materials); 656,330 / 245,240 = 2.7 (ASML); 245,240 / 14,050 = 17.5 (Onto Innovation); 393,130 / 245,240 = 1.6 (Lam Research); 245,240 / 394,116 - 1 = -38% (June to September 2026); 394,116 / 118,454 = 3.3 times (June 2025 to June 2026); price 187.92 / 307.37 - 1 = -38.9%; 187.92 / 227.35 - 1 = -17% (June buyback price); 227.35 / 187.92 = 1.21 (21% more shares); free cash flow yield 3,767.1 / 245,240 = 1.5%; research 1,532.1 / 245,240 = 0.6% of KLA market value and 1,532.1 / 14,050 = 10.9%, about a ninth, of Onto Innovation's; revenue 13,579.5 / Lam Research 23,232.7 = 58%; market value 245,240 / 393,130 = 62%; buybacks 2,289.8 / 187.92 = 12.2 million shares at the September price, 12.2 / 1,319.6 = 0.9%; authorisation 9,740 / 2,289.8 = 4.3 years at the fiscal 2026 pace; P/E 245,240 / 4,830.8 = 50.8; P/S 245,240 / 13,579.5 = 18.1. Gross margin gap 61.3% less Lam Research about 50% = about 11 points - cash flow, capital returns, balance sheet, per-share figures and valuation. — FY2015-FY2026 · publ. September 2026 · source ↗
    Method: Arithmetic on figures reported in KLA's Forms 10-K and 10-Q, quarterly results releases, XBRL filings and market data; operands shown in the source line.
Sources
Generated September 28, 2026