Corning
GLW on NYSE. Corning sells glass, fiber, and ceramic products to device, display, auto, and network makers. Market value $137.3bn.
Price checks use the past 12 months to June 2026. Quality checks use five annual reports, the latest for the year to December 2025.
Should I look at this?
Good business, but not cheap right now
Why it could be worth it
What to watch out for
See cheaper Technology stocks on the list
This is not advice. Check the numbers below.
For every $100 of what the whole company costs, it produced $1.65 of spare cash in the past 12 months. A savings account pays about $4.
You pay 58.3 years of operating profit for the business. The average large US company costs around 18.
Each dollar kept in the business earns 7 cents a year. Above 10 is good.
Quality score: 82 of 100. Price score: 16 of 100. Our list needs 70 on quality and 60 on price.
$168.97 a share, 118% above its 1-year low
Over the past year the price has ranged from $77.39 to $271.78.
Dividend: 0.7% a year
Paid every year for at least 5 years
Prices from Tuesday’s close (6 October).
Five years of cash, in billions
Spare cash swings from quarter to quarter here: $2.4 billion in the past 12 months, $1.4 billion in the year to December 2025.
| Revenue | |||||
| Revenue | $14.1bn | $14.2bn | $12.6bn | $13.1bn | $15.6bn |
| Operating margin | |||||
| Operating margin | 15.0% | 10.1% | 7.1% | 8.7% | 14.6% |
| Debt to equity | |||||
| Debt to equity | 0.57 | 0.58 | 0.65 | 0.67 | 0.71 |
| Shares outstanding | |||||
| Shares outstanding | 0.85bn | 0.85bn | 0.86bn | 0.86bn | 0.86bn |
Health checks
- Free cash flow positive5 of 5 years
- Accounting looks honest (Beneish)Nothing unusual
- Financial strength (Piotroski)6 of 8 checks we could run
- Profit backed by cash (accruals)Yes
- Debt0.71× equity
- Revenue growth, five yearsSlow, 6.7% a year
- Buying back its own sharesRoughly flat
The quarter to June 2026
How the business did, compared with the same quarter a year earlier.
- Sales: $4.5 billion last quarter, up 17% on a year ago.
- Profit: $559 million, up 19% on a year ago.
- It keeps 15 cents of each $1 of sales as operating profit, up from 12 cents a year earlier.
- Spare cash over the past 12 months: $2.4 billion, up from $1.2 billion.
- 1% more shares than a year ago. Each share owns a bit less of the company.
- Debt is $5.9 billion more than cash, down from $6 billion a year ago.
- Sales grew on a year ago in each of the last 4 quarters.
| Quarter to | Amount |
|---|---|
| September 2024 | $3.4bn |
| December 2024 | $3.5bn |
| March 2025 | $3.5bn |
| June 2025 | $3.9bn |
| September 2025 | $4.1bn |
| December 2025 | $4.2bn |
| March 2026 | $4.1bn |
| June 2026 | $4.5bn |
| Quarter to | Amount |
|---|---|
| September 2024 | -$117m |
| December 2024 | $310m |
| March 2025 | $157m |
| June 2025 | $469m |
| September 2025 | $430m |
| December 2025 | $540m |
| March 2026 | $371m |
| June 2026 | $559m |
From the company's quarterly reports to the SEC.
Dates
- Next results (estimated)
- 27 October 2026
- Last annual report (10-K)
- 12 February 2026
- Next quarterly (estimated, 10-Q)
- 28 October 2026
Who owns it
10 long-term investors we follow own it, down from 14 last quarter. 2,671 funds in all.
- GAMCO InvestorsMario Gabelli
- Value
- $40m
- Share of fund
- 0.4%
- Aristotle Capital ManagementHoward Gleicher
- Value
- $715,204
- Share of fund
- <0.1%
| Fund | Value | Share of that fund | Change |
|---|---|---|---|
| Hosking PartnersJeremy Hosking | $72m | 2.4% | Cut |
| GAMCO InvestorsMario Gabelli | $40m | 0.4% | |
| Auxier Asset ManagementJeff Auxier | $28m | 3.8% | Cut |
| Mairs & PowerAndy Adams | $22m | 0.2% | Cut |
| Gotham Asset ManagementJoel Greenblatt | $18m | <0.1% | Added |
| Dodge & CoxDodge & Cox investment committee | $9m | <0.1% | Cut |
| First Manhattan Co.First Manhattan partners | $2m | <0.1% | Added |
| Boyar Asset ManagementMark Boyar | $1m | 0.7% | Cut |
| Aristotle Capital ManagementHoward Gleicher | $715,204 | <0.1% | |
| Beutel GoodmanBeutel Goodman team | $453,000 | <0.1% | Cut |
Sold out this quarter
Largest holders overall
- BlackRock$16.8bn
- Vanguard Capital Management$13.0bn
- State Street$10.5bnAdded
- JPMorgan Chase$9.2bnAdded
- Banque Cantonale Vaudoise$7.4bnAdded
- Capital Research Global Investors$6.3bnAdded
- FMR$6.1bnCut
- Vanguard Portfolio Management$4.8bnCut
- Bank of America$4.8bnAdded
- Geode Capital Management$4.7bnCut
From 13F filings for the quarter ended 30 June 2026.
Big holders and activists
2 investors own more than 5%.
- Samsung Display Co., Ltd.Passive investor7.9%−0.4 ptsSince 20 August 2025
- Vanguard Capital ManagementPassive investor6.8%Since 31 March 2026
- The Vanguard GroupPassive investorSold down below 5%Since 13 March 2026
| Holder | Stake | Since | |
|---|---|---|---|
Samsung Display Co., Ltd. Passive investor | 7.9%−0.4 pts | 20 August 2025 | |
Vanguard Capital Management Passive investor | 6.8% | 31 March 2026 | |
The Vanguard Group Passive investor | Sold down below 5% | 13 March 2026 |
From Schedule 13D and 13G filings: anyone owning more than 5% must file one.
What insiders did
No insider bought shares on the open market in the last 12 months. 14 sold $98m.
- Gullo Michelle LSenior Vice President & CHROSold
- Date
- 4 September 2026
- Shares
- 9,874
- Price
- $152.29
- Value
- $2m
- STEVERSON LEWIS AVice Chairman, EVP and CLAOSold
- Date
- 28 August 2026
- Shares
- 13,100
- Price
- $151.29
- Value
- $2m
- WEEKS WENDELL PChairman, CEO and President, DirectorSold
- Date
- 9 June 2026
- Shares
- 100,000
- Price
- $186.46
- Value
- $19m
- Amin JayminSVP and Chief Tech. OfficerSold
- Date
- 22 May 2026
- Shares
- 27,395
- Price
- $192.14
- Value
- $5m
- Nelson Avery H IIIExecutive Vice President & COOSold
- Date
- 15 May 2026
- Shares
- 20,000
- Price
- $195.93
- Value
- $4m
- Verkleeren Ronald LSVP Emerging Innovations GroupSold
- Date
- 13 May 2026
- Shares
- 10,000
- Price
- $207.77
- Value
- $2m
- TILLMAN MICHAUNE DSVP and General CounselSold
- Date
- 11 May 2026
- Shares
- 3,260
- Price
- $207.02
- Value
- $674,885
- Seetharam SoumyaSenior Vice President & CDIOSold
- Date
- 11 May 2026
- Shares
- 20,000
- Price
- $206.23
- Value
- $4m
- Zhang John ZExec. Vice President & CCDOSold
- Date
- 11 May 2026
- Shares
- 10,000
- Price
- $198.34
- Value
- $2m
- STEVERSON LEWIS AVice Chairman, EVP and CLAOSold
- Date
- 8 May 2026
- Shares
- 27,750
- Price
- $196.06
- Value
- $5m
| Date | Who | Did | Shares | Price | Value |
|---|---|---|---|---|---|
| 4 September 2026 | Gullo Michelle L Senior Vice President & CHRO | Sold | 9,874 | $152.29 | $2m |
| 28 August 2026 | STEVERSON LEWIS A Vice Chairman, EVP and CLAO | Sold | 13,100 | $151.29 | $2m |
| 9 June 2026 | WEEKS WENDELL P Chairman, CEO and President, Director | Sold | 100,000 | $186.46 | $19m |
| 22 May 2026 | Amin Jaymin SVP and Chief Tech. Officer | Sold | 27,395 | $192.14 | $5m |
| 15 May 2026 | Nelson Avery H III Executive Vice President & COO | Sold | 20,000 | $195.93 | $4m |
| 13 May 2026 | Verkleeren Ronald L SVP Emerging Innovations Group | Sold | 10,000 | $207.77 | $2m |
| 11 May 2026 | TILLMAN MICHAUNE D SVP and General Counsel | Sold | 3,260 | $207.02 | $674,885 |
| 11 May 2026 | Seetharam Soumya Senior Vice President & CDIO | Sold | 20,000 | $206.23 | $4m |
| 11 May 2026 | Zhang John Z Exec. Vice President & CCDO | Sold | 10,000 | $198.34 | $2m |
| 8 May 2026 | STEVERSON LEWIS A Vice Chairman, EVP and CLAO | Sold | 27,750 | $196.06 | $5m |
From Form 4 filings: insiders must report trades in their own company's shares within two days.
Warning signs in its filings
Problems the company itself reported to the SEC, in its own words.
None of the warning signs we check for were found.
We look for five warning signs: doubt it can keep going, weak checks on its own accounts, a notice that its past accounts can't be relied on, a change of auditor, and one customer bringing in a big share of sales. We don't check lawsuits, investigations or debt yet.
We checked the auditor's report, internal controls, restatement notices, auditor changes and big customers in the 10-K filed 12 Feb 2026, plus the 10-Q filed 29 Jul 2026 and 9 later 8-Ks.
A 10-K is the yearly report every US company files with the SEC. An 8-K is a short notice of a big event.
What could go wrong
- It isn't cheap on profits: 58.3× operating profit.
Whether the price already reflects the risks is what the deep dive is for.
The deep dive
Everything above is arithmetic on public filings. The deep dive reads the last ten years of annual reports, the proxy statements, and the earnings calls, then argues the case the way Buffett, Klarman, and Hohn would, and checks every claim against the source.
- What the business is worth, as a range, and the margin of safety at today’s price
- Prices to start buying, buy, and buy hard
- The three things that would make this a mistake
- Every number footnoted to the filing it came from
Your first deep dive is free.
Not advice. Numbers on this page come from SEC filings and are updated each night; prices are updated again after the US market closes. The five-year figures are rounded.