TRANSMEDICS GROUP INC TMDX
COM · Common Stock · CUSIP 89377M109 · ISIN US89377M1099
- SectorHealth care
- IndustryElectromedical & Electrotherapeutic Apparatus
- HeadquartersAndover, MA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($456.7k this quarter). Holder counts are more reliable. Shares outstanding: 34.7m as of 2026-07-30, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $66.48. Options: 21 managers hold calls ($115.0m notional), 14 hold puts ($130.7m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 179 |
| Q4 2022 | 200 |
| Q1 2023 | 224 |
| Q2 2023 | 241 |
| Q3 2023 | 224 |
| Q4 2023 | 250 |
| Q1 2024 | 263 |
| Q2 2024 | 340 |
| Q3 2024 | 375 |
| Q4 2024 | 315 |
| Q1 2025 | 300 |
| Q2 2025 | 369 |
| Q3 2025 | 388 |
| Q4 2025 | 429 |
| Q1 2026 | 416 |
| Q2 2026 | 374 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 208 | 164 |
| Q4 2024 | 186 | 210 |
| Q1 2025 | 171 | 153 |
| Q2 2025 | 218 | 145 |
| Q3 2025 | 222 | 169 |
| Q4 2025 | 221 | 172 |
| Q1 2026 | 207 | 206 |
| Q2 2026 | 202 | 229 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $135.9m | $119.8m | 0.88 |
| Q4 2025 | $98.1m | $58.2m | 0.59 |
| Q1 2026 | $71.6m | $57.8m | 0.81 |
| Q2 2026 | $115.0m | $130.7m | 1.14 |
Biggest buyers
| CITADEL ADVISORS LLC | Added | +497.2k |
| BlackRock, Inc. | Added | +303.2k |
| BRAIDWELL LP | Added | +280.3k |
| Tidal Investments LLC | New | +251.2k |
| CONGRESS ASSET MANAGEMENT CO | New | +227.8k |
| Point72 Asset Management, L.P. | New | +192.6k |
| EMERALD ADVISERS, LLC | Added | +147.7k |
| HRT FINANCIAL LP | Added | +132.0k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | +121.5k |
| STATE STREET CORP | Added | +100.9k |
Biggest sellers
| Invesco Ltd. | Reduced | -643.0k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | Reduced | -541.3k |
| TWO SIGMA INVESTMENTS, LP | Reduced | -316.2k |
| GOLDMAN SACHS GROUP INC | Reduced | -306.5k |
| PRICE T ROWE ASSOCIATES INC /MD/ | Reduced | -300.7k |
| MORGAN STANLEY | Reduced | -289.0k |
| ROYCE & ASSOCIATES LP | Sold out | -244.4k |
| LORD, ABBETT & CO. LLC | Sold out | -214.0k |
| FRONTIER CAPITAL MANAGEMENT CO LLC | Reduced | -170.3k |
| Candriam S.C.A. | Sold out | -158.8k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $44.2m665.2k shares |
| CITADEL ADVISORS LLC | Added | $27.2m409.1k shares |
| JANE STREET GROUP, LLC | Added | $23.6m355.9k shares |
| IMC-Chicago, LLC | Added | $10.2m153.3k shares |
| SIMPLEX TRADING, LLC | Added | $2.9m43.5k shares |
| TUDOR INVESTMENT CORP ET AL | Added | $1.4m20.8k shares |
| GROUP ONE TRADING LLC | Reduced | $983.0k14.8k shares |
| MILLENNIUM MANAGEMENT LLC | Added | $976.4k14.7k shares |
| Walleye Capital LLC | Added | $737.3k11.1k shares |
| Perigon Wealth Management, LLC | New | $697.4k10.5k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $34.6m521.5k shares |
| Tidal Investments LLC | New | $33.2m500.0k shares |
| CITADEL ADVISORS LLC | Added | $29.8m449.3k shares |
| JANE STREET GROUP, LLC | Added | $17.2m259.4k shares |
| IMC-Chicago, LLC | Added | $9.2m137.9k shares |
| SIMPLEX TRADING, LLC | Added | $1.7m26.1k shares |
| 683 Capital Management, LLC | Unchanged | $1.3m20.0k shares |
| GROUP ONE TRADING LLC | Added | $1.0m15.7k shares |
| Point72 Asset Management, L.P. | Added | $763.8k11.5k shares |
| WOLVERINE ASSET MANAGEMENT LLC | Unchanged | $637.6k9.6k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution +2.1 pts · filed 2025-05-12 | 15.0% |
| BlackRock, Inc. 13G · institution filed 2025-07-18 | 14.6% |
| VANGUARD PORTFOLIO MANAGEMENT LLC 13G · institution new · filed 2026-04-29 | 5.7% |
| VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 | 5.1% |
Fell to 5% or below in the last year: VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD PORTFOLIO MANAGEMENT LLC)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 3 | $2.5m | $2.5m |
| Q1 2025 | 0 | — | 1 | $270.7k | $86.7k |
| Q2 2025 | 0 | — | 3 | $1.5m | $1.3m |
| Q3 2025 | 1 | $2.0m | 1 | $520.0k | $520.0k |
| Q4 2025 | 1 | $1.0m | 4 | $1.8m | $540.3k |
| Q1 2026 | 0 | — | 5 | $2.4m | — |
| Q2 2026 | 0 | — | 1 | $722.4k | — |
| Q3 2026 | 1 | $109.1k | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-09-11 | Weill David Director | Bought | $109.1k1.3k shares |
| 2026-06-15 | Gunderson Thomas J. Director | Sold | $722.4k9.6k shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.01% of their portfolio | 5.6m $371.7m | Added +303.2k |
| FMR LLC 0.01% of their portfolio | 5.1m $341.0m | Added +37.1k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.01% of their portfolio | 1.9m $128.5m | Added +14.5k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 1.5m $99.5m | Added +19.4k |
| STATE STREET CORP 0.00% of their portfolio | 1.4m $94.3m | Added +100.9k |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. 0.09% of their portfolio | 910.5k $60.5m | Added +24.7k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 894.9k $59.5m | Added +55.8k |
| Hood River Capital Management LLC 0.36% of their portfolio | 751.1k $49.9m | Added +51.4k |
| DIMENSIONAL FUND ADVISORS LP 0.01% of their portfolio | 610.1k $40.5m | Added +93.4k |
| BRAIDWELL LP 1.50% of their portfolio | 609.7k $40.5m | Added +280.3k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 559.8k $37.2m | Reduced -306.5k |
| CITADEL ADVISORS LLC 0.02% of their portfolio | 558.8k $37.1m | Added +497.2k |
| EVENTIDE ASSET MANAGEMENT, LLC 0.49% of their portfolio | 548.9k $36.5m | Added +50 |
| WELLINGTON MANAGEMENT GROUP LLP 0.01% of their portfolio | 516.0k $34.3m | Added +29.5k |
| EMERALD ADVISERS, LLC 0.77% of their portfolio | 490.5k $32.6m | Added +147.7k |
| UBS Group AG 0.01% of their portfolio | 488.1k $32.4m | Reduced -92.7k |
| MORGAN STANLEY 0.00% of their portfolio | 405.1k $26.9m | Reduced -289.0k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 398.2k $26.5m | Reduced -541.3k |
| Invesco Ltd. 0.00% of their portfolio | 395.0k $26.2m | Reduced -643.0k |
| CITIGROUP INC 0.01% of their portfolio | 386.1k $25.6m | Added +28.7k |
| Capital World Investors 0.00% of their portfolio | 384.7k $25.5m | Added +10.5k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 368.9k $24.5m | Added +30.7k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 328.7k $21.8m | Added +9.7k |
| WASATCH ADVISORS LP 0.13% of their portfolio | 308.4k $20.5m | Reduced -37.7k |
| ZEVENBERGEN CAPITAL INVESTMENTS LLC 0.47% of their portfolio | 308.4k $20.5m | Added +21.9k |
| EMERALD MUTUAL FUND ADVISERS TRUST 0.71% of their portfolio | 302.1k $20.1m | Added +72.7k |
| BAILLIE GIFFORD & CO 0.02% of their portfolio | 267.9k $17.8m | Reduced -37.3k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 260.2k $17.3m | Reduced -13.6k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 257.0k $17.1m | Reduced -38.2k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.02% of their portfolio | 255.4k $17.0m | Added +121.5k |
| Tidal Investments LLC 0.04% of their portfolio | 251.2k $16.7m | New |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 248.3k $16.5m | Reduced -57.8k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 245.7k $16.3m | Added +9.3k |
| PRINCIPAL FINANCIAL GROUP INC 0.01% of their portfolio | 240.9k $16.0m | Added +9.4k |
| BARCLAYS PLC 0.00% of their portfolio | 237.6k $15.8m | Added +47.0k |
| CONGRESS ASSET MANAGEMENT CO 0.09% of their portfolio | 227.8k $15.1m | New |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 217.0k $14.4m | Added +21.6k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 193.8k $12.9m | Reduced -17.6k |
| Point72 Asset Management, L.P. 0.02% of their portfolio | 192.6k $12.8m | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 192.3k $13.0m | Reduced -116.1k |
| FirstWave Capital Management LLC 5.61% of their portfolio | 191.2k $12.7m | Added +67.0k |
| Davidson Kempner Capital Management LP 0.18% of their portfolio | 166.9k $11.1m | Added +20.5k |
| HRT FINANCIAL LP 0.03% of their portfolio | 165.1k $11.0m | Added +132.0k |
| FRONTIER CAPITAL MANAGEMENT CO LLC 0.09% of their portfolio | 150.2k $10.0m | Reduced -170.3k |
| Public Sector Pension Investment Board 0.02% of their portfolio | 118.7k $7.9m | Reduced -3.5k |
| OPPENHEIMER & CO INC 0.08% of their portfolio | 110.8k $7.4m | Reduced -2.7k |
| RENAISSANCE GROUP LLC 0.29% of their portfolio | 108.2k $7.2m | Added +14.6k |
| Bellevue Group AG 0.14% of their portfolio | 101.1k $6.7m | Unchanged |
| Lagoda Investment Management, L.P. 3.56% of their portfolio | 97.5k $6.5m | Added +6.9k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 96.3k $6.4m | Reduced -48.2k |
| Trexquant Investment LP 0.04% of their portfolio | 94.0k $6.2m | Reduced -12.3k |
| LAZARD ASSET MANAGEMENT LLC 0.01% of their portfolio | 92.5k $6.1m | Added +27.8k |
| IMC-Chicago, LLC 0.06% of their portfolio | 90.5k $6.0m | Added +62.8k |
| BROWN CAPITAL MANAGEMENT LLC 1.19% of their portfolio | 89.8k $6.0m | Reduced -8.1k |
| Portolan Capital Management, LLC 0.20% of their portfolio | 82.4k $5.5m | Added +71.7k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 80.2k $5.3m | Reduced -9.6k |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 79.9k $5.3m | Reduced -24.8k |
| Legal & General Group Plc 0.00% of their portfolio | 79.6k $5.3m | Added +829 |
| Bastion Asset Management Inc. 1.73% of their portfolio | 79.5k $5.1m | Added +24.0k |
| Nuveen, LLC 0.00% of their portfolio | 79.3k $5.3m | Added +891 |
| DZ BANK AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main 0.00% of their portfolio | 75.1k $5.0m | New |
| AMERICAN CENTURY COMPANIES INC 0.00% of their portfolio | 70.8k $4.7m | Added +8.2k |
| BANK OF MONTREAL /CAN/ 0.00% of their portfolio | 69.6k $4.6m | Added +235 |
| PEREGRINE CAPITAL MANAGEMENT LLC 0.15% of their portfolio | 67.5k $4.5m | Added +10.4k |
| Swiss National Bank 0.00% of their portfolio | 65.4k $4.3m | Added +1.2k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 64.5k $4.3m | Reduced -50.6k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 63.5k $4.2m | Reduced -6.2k |
| Ensign Peak Advisors, Inc 0.01% of their portfolio | 57.4k $3.8m | Reduced -18.2k |
| ALGERT GLOBAL LLC 0.05% of their portfolio | 57.2k $3.8m | Added +31.7k |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 54.0k $3.6m | Added +47.0k |
| ENVESTNET ASSET MANAGEMENT INC 0.00% of their portfolio | 52.8k $3.5m | Reduced -63.7k |
| F/m Investments LLC 0.18% of their portfolio | 51.9k $3.4m | Added +11.8k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 51.7k $5.1m | Added +8.9k |
| Empowered Funds, LLC 0.02% of their portfolio | 48.2k $3.2m | New |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 48.1k $3.2m | Reduced -5.8k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 46.0k $3.1m | Reduced -300.7k |
| BESSEMER GROUP INC 0.00% of their portfolio | 45.8k $3.0m | Reduced -22 |
| Biondo Investment Advisors, LLC 0.36% of their portfolio | 44.2k $2.9m | Reduced -13.8k |
| LPL Financial LLC 0.00% of their portfolio | 42.7k $2.8m | Added +2.8k |
| CREDIT AGRICOLE S A 0.01% of their portfolio | 42.6k $2.8m | Reduced -44.7k |
| TRILLIUM ASSET MANAGEMENT, LLC 0.08% of their portfolio | 41.6k $2.8m | Added +4.2k |
| NORDEA INVESTMENT MANAGEMENT AB 0.00% of their portfolio | 40.5k $2.7m | Added +1.7k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 39.9k $2.6m | Added +2.0k |
| Universal- Beteiligungs- und Servicegesellschaft mbH 0.00% of their portfolio | 39.3k $2.6m | Reduced -7.9k |
| Atom Investors LP 0.22% of their portfolio | 36.5k $2.4m | New |
| PRUDENTIAL FINANCIAL INC 0.00% of their portfolio | 35.5k $2.4m | Reduced -26.1k |
| Holocene Advisors, LP 0.01% of their portfolio | 33.8k $2.2m | New |
| Cambridge Investment Research Advisors, Inc. 0.00% of their portfolio | 32.9k $2.2m | Added +15.5k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 32.7k $2.2m | Added +2.9k |
| NORGES BANK 0.00% of their portfolio | 30.6k $2.0m | Not comparable |
| Emerald Investment Advisers, LLC 0.13% of their portfolio | 30.5k $2.0m | Added +5.4k |
| ArrowMark Colorado Holdings LLC 0.08% of their portfolio | 30.2k $2.0m | Reduced -140.9k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 29.1k $1.9m | Reduced -1.5k |
| NEW YORK STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 28.8k $1.9m | Reduced -581 |
| Brevan Howard Capital Management LP 0.03% of their portfolio | 28.8k $1.9m | New |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 27.9k $1.9m | Added +20.2k |
| Taylor Frigon Capital Management LLC 0.84% of their portfolio | 26.9k $1.8m | Added +7.2k |
| FRED ALGER MANAGEMENT, LLC 0.01% of their portfolio | 26.7k $1.8m | Reduced -3.3k |
| Summit Creek Advisors LLC 0.60% of their portfolio | 26.7k $1.8m | New |
| Quantinno Capital Management LP 0.00% of their portfolio | 26.0k $1.7m | Added +17.9k |