Alkermes Plc
Ownership
Ownership Structure
Who owns Alkermes Plc (ALKS)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 92.5% of the shares are freely tradable; institutional investors hold 110.5%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 16.88 | 28,314,410 | +0.1 | 03/31/2026 |
| Baker Bros Advisors LP | 5.97 | 10,012,267 | +0.0 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 5.67 | 9,511,112 | +0.0 | 03/31/2026 |
| State Street Corp | 5.64 | 9,465,286 | -0.1 | 03/31/2026 |
| Vanguard Capital Management, LLC | 4.43 | 7,427,397 | +0.0 | 03/31/2026 |
| Renaissance Technologies Corp | 3.67 | 6,160,428 | -7.6 | 03/31/2026 |
| T. Rowe Price Associates, Inc. | 2.78 | 4,664,576 | -48.2 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF | 6.06 | 10,159,628 | +0.0 | 08/31/2026 |
| Vanguard MStar Total Stk Mkt Idx Invest | 3.17 | 5,315,021 | +0.3 | 07/31/2026 |
| iShares Russell 2000 ETF | 2.55 | 4,270,866 | -0.6 | 08/31/2026 |
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 |
|---|---|---|---|---|---|
| Gaffin David Joseph | EVP, CLO, Alkermes, Inc. | 223,422 | 10,433,807 $ | Sep 3, 2026 | direct |
| Nichols Christian Todd | SVP, Chief Commercial Officer | 102,193 | 4,772,413 $ | Aug 17, 2026 | direct |
| Hopkinson Craig C. | EVP R&D, Chief Medical Officer | 65,389 | 3,053,666 $ | Sep 1, 2026 | direct |
| snyderman nancy lynn MD | Director | 15,395 | 718,947 $ | Aug 3, 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 |
|---|---|---|---|---|---|---|
| Sep 3, 2026 | Gaffin David Joseph | EVP, CLO, Alkermes, Inc. | Sell | 2,034 | 48.01 | 97,652 |
| Sep 1, 2026 | Hopkinson Craig C. | EVP R&D, Chief Medical Officer | Sell | 9,000 | 46.99 | 422,874 |
| Sep 1, 2026 | Hopkinson Craig C. | EVP R&D, Chief Medical Officer | Other | 5,000 | 24.59 | 122,950 |
| Aug 17, 2026 | Nichols Christian Todd | SVP, Chief Commercial Officer | Sell | 664 | 49.65 | 32,969 |
| Aug 17, 2026 | Nichols Christian Todd | SVP, Chief Commercial Officer | Sell | 6,912 | 49.19 | 339,967 |
| Aug 3, 2026 | snyderman nancy lynn MD | Director | Sell | 44,472 | 50.35 | 2,239,076 |
| Aug 3, 2026 | snyderman nancy lynn MD | Director | Other | 16,524 | 46.72 | 772,001 |
| Aug 3, 2026 | snyderman nancy lynn MD | Director | Other | 27,948 | 46.72 | 1,305,731 |
| Aug 3, 2026 | Hopkinson Craig C. | EVP R&D, Chief Medical Officer | Sell | 9,000 | 48.58 | 437,220 |
| Aug 3, 2026 | Hopkinson Craig C. | EVP R&D, Chief Medical Officer | Other | 4,896 | 24.59 | 120,393 |
| Aug 3, 2026 | Hopkinson Craig C. | EVP R&D, Chief Medical Officer | Other | 104 | 19.34 | 2,011 |
| Aug 3, 2026 | Gaffin David Joseph | EVP, CLO, Alkermes, Inc. | Sell | 2,034 | 48.58 | 98,812 |
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.