ADTRAN Inc
Ownership
Ownership Structure
Who owns ADTRAN Inc (ADTN)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 97.4% of the shares are freely tradable; institutional investors hold 105.7%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 9.62 | 7,840,254 | -3.5 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 5.86 | 4,771,452 | +0.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 4.20 | 3,426,230 | +0.0 | 03/31/2026 |
| Royce & Associates, LP | 3.84 | 3,127,403 | +20.4 | 03/31/2026 |
| Two Sigma Investments LLC | 3.55 | 2,896,353 | +157.8 | 06/30/2026 |
| Millennium Management LLC | 3.34 | 2,722,820 | +43.6 | 06/30/2026 |
| DnB NOR Asset Management (Asia) | 3.21 | 2,619,389 | -16.1 | 06/30/2026 |
| Arnhold & S. Bleichroeder Advisers, LLC | 3.06 | 2,497,014 | +82.4 | 06/30/2026 |
| State Street Corp | 2.89 | 2,350,737 | +18.4 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 3.15 | 2,569,422 | +0.0 | 07/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Glingener Christoph | Chief Technology Officer | 83,953 | 596,066 $ | Aug 10, 2026 | direct |
| Santo Timothy P | SVP of Finance; CFO | 59,924 | 425,460 $ | Aug 6, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 10, 2026 | Glingener Christoph | Chief Technology Officer | Other | 27,924 | 0.00 | – |
| Aug 6, 2026 | Santo Timothy P | SVP of Finance; CFO | Buy | 6,579 | 7.60 | 50,000 |
| Jul 24, 2026 | Glingener Christoph | Chief Technology Officer | Other | 9,384 | 0.00 | – |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.