Who owns Neuronetics (STIM)
Which tracked institutional funds hold STIM, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See STIM company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 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 STIM is one-sided between 2026-Q1 and 2026-Q2: 3 added or opened and 10 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
STIM’s largest tracked holder by dollar value, Madryn Asset Management, LP, sizes it at 65.3% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 65.3pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in STIM 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 2026-Q1 and 2026-Q2, across 84 tracked filers holding STIM, 44 increased or opened the position and 55 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 STIM between the 2026-Q1 and 2026-Q2 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 1
- MARSHALL WACE, LLP$631K
Full exits 2
- BALYASNY ASSET MANAGEMENT L.P.$4M
- HighTower Advisors, LLC$815K
Largest adds
- WEXFORD CAPITAL LP$2M
- CITADEL ADVISORS LLC$437K
Largest trims
- Madryn Asset Management, LP$3M
- BlackRock, Inc.$3M
- UBS Group AG$1M
- VANGUARD CAPITAL MANAGEMENT LLC$1M
- STATE STREET CORP$844K
- GEODE CAPITAL MANAGEMENT, LLC$795K
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 |
|---|---|---|---|---|
| Madryn Asset Management, LP added | 18,540,488 | $24M | 37.8% | 2026-Q2 |
| UBS Group AG trimmed | 2,279,099 | $3M | 4.6% | 2026-Q2 |
| WEXFORD CAPITAL LP added | 2,002,625 | $3M | 4.1% | 2026-Q2 |
| FourWorld Capital Management LLC added | 1,744,142 | $2M | 3.6% | 2026-Q2 |
| Lane Generational LLC trimmed | 1,633,372 | $2M | 3.3% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC trimmed | 1,507,097 | $2M | 3.1% | 2026-Q2 |
| MASTERS CAPITAL MANAGEMENT LLC | 1,000,000 | $1M | 2.0% | 2026-Q2 |
| AdvisorShares Investments LLC added | 742,795 | $966K | 1.5% | 2026-Q2 |
| Ikarian Capital, LLC | 701,182 | $912K | 1.4% | 2026-Q2 |
| BlackRock, Inc. trimmed | 596,622 | $776K | 1.2% | 2026-Q2 |
| MARSHALL WACE, LLP added | 485,692 | $631K | 1.0% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 458,474 | $596K | 0.9% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 421,903 | $548K | 0.9% | 2026-Q2 |
| Dauntless Investment Group, LLC added | 369,187 | $480K | 0.8% | 2026-Q2 |
| STATE STREET CORP trimmed | 290,299 | $377K | 0.6% | 2026-Q2 |
| Centiva Capital, LP added | 285,913 | $372K | 0.6% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 264,734 | $344K | 0.5% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 264,088 | $343K | 0.5% | 2026-Q2 |
| JBF Capital, Inc. | 233,166 | $303K | 0.5% | 2026-Q2 |
| XTX Topco Ltd added | 220,323 | $286K | 0.4% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC added | 199,450 | $259K | 0.4% | 2026-Q2 |
| BOOTHBAY FUND MANAGEMENT, LLC | 189,263 | $246K | 0.4% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 185,753 | $241K | 0.4% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 185,250 | $241K | 0.4% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS added | 148,815 | $193K | 0.3% | 2026-Q2 |
| TUDOR INVESTMENT CORP ET AL new | 124,861 | $162K | 0.3% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 117,822 | $153K | 0.2% | 2026-Q2 |
| ADAR1 Capital Management, LLC | 100,000 | $130K | 0.2% | 2026-Q2 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 95,205 | $124K | 0.2% | 2026-Q2 |
| Squarepoint Ops LLC added | 94,616 | $123K | 0.2% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 89,138 | $116K | 0.2% | 2026-Q2 |
| GAMCO INVESTORS, INC. ET AL | 79,200 | $103K | 0.2% | 2026-Q2 |
| Invesco Ltd. trimmed | 68,340 | $89K | 0.1% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 68,195 | $89K | 0.1% | 2026-Q2 |
| MORGAN STANLEY added | 62,893 | $82K | 0.1% | 2026-Q2 |
| Engineers Gate Manager LP added | 57,175 | $74K | 0.1% | 2026-Q2 |
| VestGen Advisors, LLC trimmed | 50,279 | $65K | 0.1% | 2026-Q2 |
| Cruiser Capital Advisors, LLC | 48,900 | $64K | 0.1% | 2026-Q2 |
| Caitong International Asset Management Co., Ltd trimmed | 41,320 | $54K | 0.1% | 2026-Q2 |
| Arax Advisory Partners added | 39,843 | $52K | 0.1% | 2026-Q2 |
| HSBC HOLDINGS PLC new | 37,847 | $50K | 0.1% | 2026-Q2 |
| GABELLI FUNDS LLC | 38,000 | $49K | 0.1% | 2026-Q2 |
| Quadrature Capital Ltd added | 30,856 | $40K | 0.1% | 2026-Q2 |
| David J Yvars Group added | 27,550 | $36K | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ trimmed | 24,246 | $32K | 0.1% | 2026-Q2 |
| State of Wyoming new | 23,482 | $31K | 0.0% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 23,211 | $30K | 0.0% | 2026-Q2 |
| Fielder Capital Group LLC added | 22,903 | $30K | 0.0% | 2026-Q2 |
| Composition Wealth, LLC new | 19,851 | $26K | 0.0% | 2026-Q2 |
| Tower Research Capital LLC (TRC) added | 19,602 | $25K | 0.0% | 2026-Q2 |
| GROUP ONE TRADING LLC trimmed | 17,669 | $23K | 0.0% | 2026-Q2 |
| Vanguard Global Advisers, LLC | 16,453 | $21K | 0.0% | 2026-Q2 |
| Aigen Investment Management, LP new | 16,246 | $21K | 0.0% | 2026-Q2 |
| SIMPLEX TRADING, LLC added | 14,861 | $19K | 0.0% | 2026-Q2 |
| IMC-Chicago, LLC trimmed | 14,566 | $19K | 0.0% | 2026-Q2 |
| StoneX Group Inc. trimmed | 12,092 | $19K | 0.0% | 2026-Q2 |
| Pathstone Holdings, LLC trimmed | 14,247 | $19K | 0.0% | 2026-Q2 |
| BANK OF MONTREAL /CAN/ new | 14,109 | $18K | 0.0% | 2026-Q2 |
| AXQ CAPITAL, LP trimmed | 11,024 | $14K | 0.0% | 2026-Q2 |
| ROYAL BANK OF CANADA trimmed | 11,158 | $14K | 0.0% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 8,839 | $11K | 0.0% | 2026-Q2 |
| BARCLAYS PLC trimmed | 5,839 | $8K | 0.0% | 2026-Q2 |
| FMR LLC trimmed | 5,061 | $7K | 0.0% | 2026-Q2 |
| MCF Advisors LLC | 3,564 | $5K | 0.0% | 2026-Q2 |
| CITIGROUP INC trimmed | 2,619 | $3K | 0.0% | 2026-Q2 |
| Rockefeller Capital Management L.P. | 1,500 | $2K | 0.0% | 2026-Q2 |
| Essential Partners LLC trimmed | 835 | $1K | 0.0% | 2026-Q2 |
| OSAIC HOLDINGS, INC. | 795 | $1K | 0.0% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 748 | $1K | 0.0% | 2026-Q2 |
| Physician Wealth Advisors, Inc. | 775 | $1K | 0.0% | 2026-Q2 |
| GAMMA Investing LLC trimmed | 681 | $885 | 0.0% | 2026-Q2 |
| EverSource Wealth Advisors, LLC added | 606 | $788 | 0.0% | 2026-Q2 |
| Allied Private Wealth LLC new | 470 | $723 | 0.0% | 2026-Q2 |
| SBI Securities Co., Ltd. added | 458 | $595 | 0.0% | 2026-Q2 |
| Integrated Wealth Concepts LLC new | 323 | $420 | 0.0% | 2026-Q2 |
| Farther Finance Advisors, LLC added | 226 | $294 | 0.0% | 2026-Q2 |
| Allworth Financial LP added | 169 | $220 | 0.0% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN trimmed | 150 | $195 | 0.0% | 2026-Q2 |
| PNC Financial Services Group, Inc. trimmed | 124 | $161 | 0.0% | 2026-Q2 |
| Transamerica Financial Advisors, LLC new | 119 | $154 | 0.0% | 2026-Q2 |
| Federation des caisses Desjardins du Quebec | 104 | $134 | 0.0% | 2026-Q2 |
| ROTHSCHILD INVESTMENT LLC added | 83 | $108 | 0.0% | 2026-Q2 |
| TD Waterhouse Canada Inc. | 59 | $80 | 0.0% | 2026-Q2 |
| IFP Advisors, Inc added | 12 | $16 | 0.0% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. added | 2,743,768 | $4M | 6.2% | 2026-Q1 stale (1 quarter behind) |
| HighTower Advisors, LLC trimmed | 562,370 | $815K | 1.3% | 2026-Q1 stale (1 quarter behind) |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 221,170 | $321K | 0.5% | 2026-Q1 stale (1 quarter behind) |
| Massar Capital Management, LP | 221,000 | $320K | 0.5% | 2026-Q1 stale (1 quarter behind) |
| VANGUARD GROUP INC trimmed | 2,582,382 | $4M | 5.6% | 2025-Q4 stale (2 quarters behind) |
| RENAISSANCE TECHNOLOGIES LLC added | 474,900 | $655K | 1.0% | 2025-Q4 stale (2 quarters behind) |
| TWO SIGMA INVESTMENTS, LP trimmed | 198,745 | $274K | 0.4% | 2025-Q4 stale (2 quarters behind) |
| TWO SIGMA ADVISERS, LP added | 169,000 | $233K | 0.4% | 2025-Q4 stale (2 quarters behind) |
| Aristides Capital LLC new | 136,400 | $188K | 0.3% | 2025-Q4 stale (2 quarters behind) |
| EHP Funds Inc. new | 209,385 | $572K | 0.9% | 2025-Q3 stale (3 quarters behind) |
| Sanctuary Advisors, LLC | 88,931 | $327K | 0.5% | 2025-Q3 stale (3 quarters behind) |
| Manatuck Hill Partners, LLC | 920,000 | $3M | 5.0% | 2025-Q2 stale (4 quarters behind) |
| AWM Investment Company, Inc. | 245,924 | $858K | 1.3% | 2025-Q2 stale (4 quarters behind) |
| CenterBook Partners LP trimmed | 106,650 | $372K | 0.6% | 2025-Q2 stale (4 quarters behind) |
| Bay Colony Advisory Group, Inc d/b/a Bay Colony Advisors added | 86,919 | $303K | 0.5% | 2025-Q2 stale (4 quarters behind) |
| NKCFO LLC trimmed | 75,000 | $262K | 0.4% | 2025-Q2 stale (4 quarters behind) |
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.