Who owns Select Medical Holdings (SEM)
Which tracked institutional funds hold SEM, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See SEM 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.
Conviction spread
SEM’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes SEM more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in SEM 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, we do not read how tracked institutions changed their SEM positions: many holders could not be matched across the two filings, most often because the security’s identifier changed and our mapping is incomplete, or because funds are still filing for the newer quarter. Over the same quarter, there were no open-market insider Form 4s.
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
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 13,073,640 | $216M | 17.8% | 2026-Q2 |
| Verition Fund Management LLC added | 12,025,235 | $199M | 16.4% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 5,518,861 | $91M | 7.5% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 4,943,691 | $82M | 6.7% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 4,506,456 | $74M | 6.1% | 2026-Q2 |
| AQR Arbitrage LLC added | 2,880,889 | $48M | 3.9% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC added | 2,754,016 | $45M | 3.8% | 2026-Q2 |
| Polar Asset Management Partners Inc. added | 2,362,979 | $39M | 3.2% | 2026-Q2 |
| HSBC HOLDINGS PLC added | 2,246,658 | $37M | 3.1% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. added | 1,623,940 | $27M | 2.2% | 2026-Q2 |
| STATE STREET CORP trimmed | 1,493,609 | $25M | 2.0% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 1,450,063 | $24M | 2.0% | 2026-Q2 |
| ALPINE ASSOCIATES MANAGEMENT INC. added | 1,304,404 | $22M | 1.8% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 1,289,169 | $21M | 1.8% | 2026-Q2 |
| ODDO BHF ASSET MANAGEMENT SAS new | 1,205,000 | $20M | 1.6% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 1,093,051 | $18M | 1.5% | 2026-Q2 |
| Westchester Capital Management, LLC new | 983,315 | $16M | 1.3% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 871,540 | $14M | 1.2% | 2026-Q2 |
| Woodline Partners LP trimmed | 860,622 | $14M | 1.2% | 2026-Q2 |
| D. E. Shaw & Co., Inc. trimmed | 798,290 | $13M | 1.1% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 772,843 | $13M | 1.1% | 2026-Q2 |
| MORGAN STANLEY trimmed | 511,408 | $8M | 0.7% | 2026-Q2 |
| Nuveen, LLC added | 411,906 | $7M | 0.6% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 399,224 | $7M | 0.5% | 2026-Q2 |
| Public Sector Pension Investment Board trimmed | 379,176 | $6M | 0.5% | 2026-Q2 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 300,000 | $5M | 0.4% | 2026-Q2 |
| Groupe la Francaise | 282,497 | $5M | 0.4% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 242,992 | $4M | 0.3% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 225,710 | $4M | 0.3% | 2026-Q2 |
| Legal & General Group Plc trimmed | 214,193 | $4M | 0.3% | 2026-Q2 |
| Swiss National Bank trimmed | 211,600 | $3M | 0.3% | 2026-Q2 |
| Man Group plc trimmed | 210,395 | $3M | 0.3% | 2026-Q2 |
| Maven Securities LTD new | 203,300 | $3M | 0.3% | 2026-Q2 |
| TUDOR INVESTMENT CORP ET AL added | 201,568 | $3M | 0.3% | 2026-Q2 |
| BLUEFIN CAPITAL MANAGEMENT, LLC new | 200,000 | $3M | 0.3% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 191,396 | $3M | 0.3% | 2026-Q2 |
| BOOTHBAY FUND MANAGEMENT, LLC added | 182,907 | $3M | 0.2% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC trimmed | 182,077 | $3M | 0.2% | 2026-Q2 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM trimmed | 177,000 | $3M | 0.2% | 2026-Q2 |
| OMERS ADMINISTRATION Corp added | 175,800 | $3M | 0.2% | 2026-Q2 |
| Carmignac Gestion | 174,516 | $3M | 0.2% | 2026-Q2 |
| CREDIT INDUSTRIEL ET COMMERCIAL | 167,503 | $3M | 0.2% | 2026-Q2 |
| NORGES BANK added | 167,058 | $3M | 0.2% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 166,669 | $3M | 0.2% | 2026-Q2 |
| Versor Investments LP added | 162,328 | $3M | 0.2% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 161,356 | $3M | 0.2% | 2026-Q2 |
| UBS Group AG trimmed | 154,804 | $3M | 0.2% | 2026-Q2 |
| Hudson Bay Capital Management LP | 150,970 | $2M | 0.2% | 2026-Q2 |
| GABELLI FUNDS LLC trimmed | 145,200 | $2M | 0.2% | 2026-Q2 |
| Linden Thomas Advisory Services, LLC added | 132,915 | $2M | 0.2% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 130,917 | $2M | 0.2% | 2026-Q2 |
| TEACHER RETIREMENT SYSTEM OF TEXAS trimmed | 128,689 | $2M | 0.2% | 2026-Q2 |
| GABELLI & Co INVESTMENT ADVISERS, INC. trimmed | 119,550 | $2M | 0.2% | 2026-Q2 |
| Russell Investments Group, Ltd. trimmed | 119,079 | $2M | 0.2% | 2026-Q2 |
| OP Asset Management Ltd | 101,953 | $2M | 0.1% | 2026-Q2 |
| PRUDENTIAL FINANCIAL INC trimmed | 94,437 | $2M | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ trimmed | 94,296 | $2M | 0.1% | 2026-Q2 |
| INTECH INVESTMENT MANAGEMENT LLC added | 90,277 | $1M | 0.1% | 2026-Q2 |
| WATER ISLAND CAPITAL LLC trimmed | 82,492 | $1M | 0.1% | 2026-Q2 |
| Point72 Asset Management, L.P. trimmed | 80,629 | $1M | 0.1% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd trimmed | 77,393 | $1M | 0.1% | 2026-Q2 |
| FRANKLIN RESOURCES INC trimmed | 73,350 | $1M | 0.1% | 2026-Q2 |
| Shay Capital LLC new | 71,100 | $1M | 0.1% | 2026-Q2 |
| Y-Intercept (Hong Kong) Ltd trimmed | 69,442 | $1M | 0.1% | 2026-Q2 |
| Creative Planning added | 66,929 | $1M | 0.1% | 2026-Q2 |
| Blackstone Inc. trimmed | 65,484 | $1M | 0.1% | 2026-Q2 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC trimmed | 63,600 | $1M | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC | 60,340 | $996K | 0.1% | 2026-Q2 |
| CSS LLC/IL added | 60,000 | $990K | 0.1% | 2026-Q2 |
| OCCUDO QUANTITATIVE STRATEGIES LP trimmed | 55,762 | $921K | 0.1% | 2026-Q2 |
| Jupiter Topco LLC new | 50,821 | $839K | 0.1% | 2026-Q2 |
| Quantinno Capital Management LP added | 49,993 | $825K | 0.1% | 2026-Q2 |
| Louisiana State Employees Retirement System | 48,900 | $797K | 0.1% | 2026-Q2 |
| OXFORD ASSET MANAGEMENT LLP | 43,929 | $725K | 0.1% | 2026-Q2 |
| STRS OHIO | 41,000 | $678K | 0.1% | 2026-Q2 |
| PenderFund Capital Management Ltd. added | 40,600 | $670K | 0.1% | 2026-Q2 |
| One68 Global Capital, LLC new | 40,000 | $691K | 0.1% | 2026-Q2 |
| Zurcher Kantonalbank (Zurich Cantonalbank) | 39,839 | $658K | 0.1% | 2026-Q2 |
| TWO SIGMA SECURITIES, LLC trimmed | 39,731 | $656K | 0.1% | 2026-Q2 |
| Sanctuary Advisors, LLC added | 37,508 | $619K | 0.1% | 2026-Q2 |
| GTS SECURITIES LLC new | 37,327 | $616K | 0.1% | 2026-Q2 |
| Gotham Asset Management, LLC trimmed | 37,138 | $613K | 0.1% | 2026-Q2 |
| PRELUDE CAPITAL MANAGEMENT, LLC trimmed | 36,600 | $604K | 0.0% | 2026-Q2 |
| Blueshift Asset Management, LLC added | 34,830 | $575K | 0.0% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. trimmed | 34,608 | $564K | 0.0% | 2026-Q2 |
| BAILARD, INC. | 33,300 | $550K | 0.0% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 32,664 | $539K | 0.0% | 2026-Q2 |
| ROYAL BANK OF CANADA added | 30,624 | $505K | 0.0% | 2026-Q2 |
| LEUTHOLD GROUP, LLC | 30,357 | $501K | 0.0% | 2026-Q2 |
| FMR LLC added | 29,775 | $492K | 0.0% | 2026-Q2 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE trimmed | 29,189 | $482K | 0.0% | 2026-Q2 |
| ARIZONA STATE RETIREMENT SYSTEM trimmed | 29,087 | $480K | 0.0% | 2026-Q2 |
| YOUSIF CAPITAL MANAGEMENT, LLC trimmed | 28,730 | $474K | 0.0% | 2026-Q2 |
| MARSHALL WACE, LLP added | 28,591 | $472K | 0.0% | 2026-Q2 |
| Atom Investors LP trimmed | 27,779 | $459K | 0.0% | 2026-Q2 |
| Skandinaviska Enskilda Banken AB (publ) trimmed | 26,865 | $444K | 0.0% | 2026-Q2 |
| BARCLAYS PLC trimmed | 26,385 | $436K | 0.0% | 2026-Q2 |
| FIFTH THIRD BANCORP added | 25,308 | $418K | 0.0% | 2026-Q2 |
| Sovereign Financial Group, Inc. added | 25,195 | $416K | 0.0% | 2026-Q2 |
| Centiva Capital, LP trimmed | 25,000 | $413K | 0.0% | 2026-Q2 |
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.