Who owns Aldeyra Therapeutics, Inc. (ALDX)
Which tracked institutional funds hold ALDX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ALDX company fundamentals →
Ownership as of the 2026-Q1 13F filings. 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on ALDX is one-sided between 2025-Q4 and 2026-Q1: 6 added or opened and 38 trimmed or exited — on balance reducing.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
ALDX’s largest tracked holder by dollar value, PERCEPTIVE ADVISORS LLC, sizes it at 0.4% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.4pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ALDX divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 124 tracked filers holding ALDX, 71 increased or opened the position and 69 reduced or closed it; over the same quarter, open-market insider Form 4s were net purchases.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in ALDX between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 4
- VANGUARD CAPITAL MANAGEMENT LLC$4M
- VANGUARD PORTFOLIO MANAGEMENT LLC$1M
- Propel Bio Management, LLC$1M
- VANGUARD FIDUCIARY TRUST CO$572K
Full exits 4
- PERCEPTIVE ADVISORS LLC$22M
- VANGUARD GROUP INC$19M
- 1492 Capital Management LLC$1M
- TWO SIGMA ADVISERS, LP$631K
Largest adds
- MILLENNIUM MANAGEMENT LLC$1M
- UBS Group AG$413K
Largest trims
- Knoll Capital Management, LLC$19M
- BlackRock, Inc.$14M
- KENNEDY CAPITAL MANAGEMENT LLC$6M
- KINGDON CAPITAL MANAGEMENT, L.L.C.$6M
- D. E. Shaw & Co., Inc.$6M
- ARDSLEY ADVISORY PARTNERS LP$6M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| Knoll Capital Management, LLC | 5,475,516 | $9M | 8.1% | 2026-Q1 |
| BlackRock, Inc. trimmed | 3,763,887 | $6M | 5.6% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 2,780,875 | $5M | 4.1% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 2,363,742 | $4M | 3.5% | 2026-Q1 |
| KINGDON CAPITAL MANAGEMENT, L.L.C. added | 2,152,315 | $4M | 3.2% | 2026-Q1 |
| 683 Capital Management, LLC trimmed | 1,500,000 | $3M | 2.2% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 1,403,990 | $2M | 2.1% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,251,652 | $2M | 1.9% | 2026-Q1 |
| STATE STREET CORP added | 1,124,710 | $2M | 1.7% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 995,243 | $2M | 1.5% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 968,891 | $2M | 1.4% | 2026-Q1 |
| ARDSLEY ADVISORY PARTNERS LP trimmed | 950,000 | $2M | 1.4% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 863,187 | $1M | 1.3% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 858,288 | $1M | 1.3% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 807,778 | $1M | 1.2% | 2026-Q1 |
| JACOBS LEVY EQUITY MANAGEMENT, INC trimmed | 796,816 | $1M | 1.2% | 2026-Q1 |
| Propel Bio Management, LLC new | 730,606 | $1M | 1.1% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 624,170 | $1M | 0.9% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 543,146 | $918K | 0.8% | 2026-Q1 |
| UBS Group AG added | 537,569 | $908K | 0.8% | 2026-Q1 |
| MORGAN STANLEY trimmed | 518,642 | $877K | 0.8% | 2026-Q1 |
| NORTHERN TRUST CORP trimmed | 374,812 | $633K | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 338,621 | $572K | 0.5% | 2026-Q1 |
| HRT FINANCIAL LP added | 286,444 | $484K | 0.4% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 278,442 | $471K | 0.4% | 2026-Q1 |
| WOODSTOCK CORP | 266,756 | $451K | 0.4% | 2026-Q1 |
| IEQ CAPITAL, LLC added | 266,518 | $450K | 0.4% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 266,340 | $450K | 0.4% | 2026-Q1 |
| GSA CAPITAL PARTNERS LLP added | 247,194 | $418K | 0.4% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP trimmed | 223,537 | $378K | 0.3% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 215,332 | $364K | 0.3% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. trimmed | 68,140 | $353K | 0.3% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN trimmed | 189,729 | $321K | 0.3% | 2026-Q1 |
| Invesco Ltd. added | 169,698 | $287K | 0.3% | 2026-Q1 |
| ExodusPoint Capital Management, LP added | 167,604 | $283K | 0.2% | 2026-Q1 |
| Caption Management, LLC added | 165,000 | $279K | 0.2% | 2026-Q1 |
| Palo Alto Investors LP trimmed | 155,709 | $263K | 0.2% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 148,962 | $252K | 0.2% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 139,029 | $235K | 0.2% | 2026-Q1 |
| Bank of New York Mellon Corp added | 136,746 | $231K | 0.2% | 2026-Q1 |
| MARSHALL WACE, LLP trimmed | 129,693 | $219K | 0.2% | 2026-Q1 |
| KENNEDY CAPITAL MANAGEMENT LLC trimmed | 95,862 | $162K | 0.1% | 2026-Q1 |
| Mariner, LLC added | 91,870 | $155K | 0.1% | 2026-Q1 |
| CWM, LLC added | 91,623 | $155K | 0.1% | 2026-Q1 |
| FOX RUN MANAGEMENT, L.L.C. added | 90,964 | $153K | 0.1% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 87,078 | $147K | 0.1% | 2026-Q1 |
| Russell Investments Group, Ltd. trimmed | 84,300 | $142K | 0.1% | 2026-Q1 |
| Cerity Partners LLC added | 81,223 | $137K | 0.1% | 2026-Q1 |
| XTX Topco Ltd added | 75,166 | $127K | 0.1% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 73,772 | $125K | 0.1% | 2026-Q1 |
| RHUMBLINE ADVISERS trimmed | 69,205 | $117K | 0.1% | 2026-Q1 |
| STRS OHIO | 68,200 | $115K | 0.1% | 2026-Q1 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC added | 61,087 | $101K | 0.1% | 2026-Q1 |
| FLOW TRADERS U.S. LLC new | 55,521 | $94K | 0.1% | 2026-Q1 |
| CAPTRUST FINANCIAL ADVISORS added | 52,947 | $89K | 0.1% | 2026-Q1 |
| Graham Capital Management, L.P. trimmed | 51,592 | $87K | 0.1% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 50,271 | $85K | 0.1% | 2026-Q1 |
| CANADA PENSION PLAN INVESTMENT BOARD added | 47,400 | $80K | 0.1% | 2026-Q1 |
| PERCEPTIVE ADVISORS LLC trimmed | 4,185,632 | $22M | 19.1% | 2025-Q4 stale |
| VANGUARD GROUP INC added | 3,698,682 | $19M | 16.9% | 2025-Q4 stale |
| 1492 Capital Management LLC new | 223,317 | $1M | 1.0% | 2025-Q4 stale |
| ADAR1 Capital Management, LLC added | 249,920 | $957K | 0.8% | 2025-Q2 stale |
| Trexquant Investment LP added | 158,117 | $909K | 0.8% | 2025-Q1 stale |
| Y-Intercept (Hong Kong) Ltd added | 138,091 | $721K | 0.6% | 2025-Q3 stale |
| TWO SIGMA ADVISERS, LP trimmed | 121,900 | $631K | 0.6% | 2025-Q4 stale |
| Cubist Systematic Strategies, LLC added | 101,375 | $529K | 0.5% | 2025-Q3 stale |
| Point72 Asset Management, L.P. added | 94,094 | $487K | 0.4% | 2025-Q4 stale |
| GROUP ONE TRADING LLC trimmed | 83,449 | $432K | 0.4% | 2025-Q4 stale |
| STATE OF WISCONSIN INVESTMENT BOARD added | 81,366 | $421K | 0.4% | 2025-Q4 stale |
| Hennion & Walsh Asset Management, Inc. trimmed | 69,442 | $399K | 0.4% | 2025-Q1 stale |
| PANAGORA ASSET MANAGEMENT INC added | 72,059 | $276K | 0.2% | 2025-Q2 stale |
| ALPS ADVISORS INC trimmed | 43,803 | $252K | 0.2% | 2025-Q1 stale |
| Quantinno Capital Management LP trimmed | 45,988 | $238K | 0.2% | 2025-Q4 stale |
| Kennondale Capital Management LLC trimmed | 56,729 | $217K | 0.2% | 2025-Q2 stale |
| Verition Fund Management LLC added | 37,505 | $216K | 0.2% | 2025-Q1 stale |
| ACT CAPITAL MANAGEMENT, LLC added | 41,000 | $212K | 0.2% | 2025-Q4 stale |
| SIMPLEX TRADING, LLC added | 39,755 | $206K | 0.2% | 2025-Q4 stale |
| FRANKLIN RESOURCES INC new | 32,346 | $186K | 0.2% | 2025-Q1 stale |
| AMERIPRISE FINANCIAL INC trimmed | 35,304 | $183K | 0.2% | 2025-Q4 stale |
| SEI INVESTMENTS CO trimmed | 33,287 | $172K | 0.2% | 2025-Q4 stale |
| AMERICAN CENTURY COMPANIES INC added | 32,460 | $168K | 0.1% | 2025-Q4 stale |
| MetLife Investment Management, LLC added | 29,531 | $153K | 0.1% | 2025-Q4 stale |
| Corebridge Financial, Inc. trimmed | 24,406 | $140K | 0.1% | 2025-Q1 stale |
| AXQ CAPITAL, LP new | 26,810 | $139K | 0.1% | 2025-Q4 stale |
| Joseph P. Lucia & Associates, LLC trimmed | 26,732 | $138K | 0.1% | 2025-Q4 stale |
| Jump Financial, LLC trimmed | 24,480 | $127K | 0.1% | 2025-Q4 stale |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 23,858 | $124K | 0.1% | 2025-Q4 stale |
| BRIGHTON JONES LLC added | 19,945 | $104K | 0.1% | 2025-Q3 stale |
| Quadrature Capital Ltd new | 19,275 | $101K | 0.1% | 2025-Q3 stale |
| Walleye Capital LLC trimmed | 18,595 | $96K | 0.1% | 2025-Q4 stale |
| Pallas Capital Advisors LLC trimmed | 17,338 | $90K | 0.1% | 2025-Q4 stale |
| STIFEL FINANCIAL CORP added | 14,935 | $86K | 0.1% | 2025-Q1 stale |
| PFG Investments, LLC trimmed | 15,500 | $80K | 0.1% | 2025-Q4 stale |
| WOLVERINE TRADING, LLC trimmed | 12,028 | $80K | 0.1% | 2025-Q1 stale |
| JONES FINANCIAL COMPANIES LLLP new | 15,000 | $78K | 0.1% | 2025-Q4 stale |
| Regal Investment Advisors LLC added | 13,565 | $70K | 0.1% | 2025-Q4 stale |
| PUBLIC EMPLOYEES RETIREMENT SYSTEM OF OHIO | 13,388 | $69K | 0.1% | 2025-Q4 stale |
| HSBC HOLDINGS PLC added | 11,543 | $69K | 0.1% | 2025-Q1 stale |
| Brooklyn Investment Group added | 12,691 | $66K | 0.1% | 2025-Q3 stale |
| Inscription Capital, LLC new | 12,633 | $66K | 0.1% | 2025-Q3 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.