COMPASS THERAPEUTICS INC CMPX
COM · Common Stock · CUSIP 20454B104
- SectorHealth care
- IndustryBiological Products, (No Diagnostic Substances)
- HeadquartersBoston, 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 ($12.5k this quarter). Holder counts are more reliable. Shares outstanding: 180.1m as of 2026-07-28, 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 ≈ $2.19. Options: 6 managers hold calls ($903.7k notional), 4 hold puts ($317.1k).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 38 |
| Q4 2022 | 56 |
| Q1 2023 | 74 |
| Q2 2023 | 74 |
| Q3 2023 | 77 |
| Q4 2023 | 78 |
| Q1 2024 | 79 |
| Q2 2024 | 83 |
| Q3 2024 | 80 |
| Q4 2024 | 93 |
| Q1 2025 | 109 |
| Q2 2025 | 104 |
| Q3 2025 | 125 |
| Q4 2025 | 173 |
| Q1 2026 | 201 |
| Q2 2026 | 216 |
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 | 38 | 33 |
| Q4 2024 | 52 | 23 |
| Q1 2025 | 56 | 38 |
| Q2 2025 | 43 | 65 |
| Q3 2025 | 77 | 40 |
| Q4 2025 | 113 | 45 |
| Q1 2026 | 119 | 65 |
| Q2 2026 | 148 | 89 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $3.6m | $12.6k | 0.00 |
| Q4 2025 | $1.6k | $9.7k | 6.00 |
| Q1 2026 | $19.2m | $1.1m | 0.06 |
| Q2 2026 | $903.7k | $317.1k | 0.35 |
Biggest buyers
| Palo Alto Investors LP | Added | +4.3m |
| MILLENNIUM MANAGEMENT LLC | Added | +3.9m |
| AQR CAPITAL MANAGEMENT LLC | Added | +3.3m |
| STATE STREET CORP | Added | +3.3m |
| CITADEL ADVISORS LLC | Added | +2.8m |
| VANGUARD PORTFOLIO MANAGEMENT LLC | Added | +2.7m |
| BlackRock, Inc. | Added | +1.8m |
| GOLDMAN SACHS GROUP INC | Added | +1.5m |
| KINGDON CAPITAL MANAGEMENT, L.L.C. | New | +1.4m |
| TANG CAPITAL MANAGEMENT LLC | Added | +1.2m |
Biggest sellers
| BVF INC/IL | Sold out | -7.8m |
| ADAGE CAPITAL PARTNERS GP, L.L.C. | Reduced | -7.3m |
| RTW INVESTMENTS, LP | Sold out | -4.2m |
| DEERFIELD MANAGEMENT COMPANY, L.P. | Sold out | -3.6m |
| Logos Global Management LP | Sold out | -3.1m |
| Sofinnova Investments, Inc. | Sold out | -2.1m |
| BRAIDWELL LP | Sold out | -2.0m |
| Vivo Capital, LLC | Reduced | -1.8m |
| UBS Group AG | Reduced | -1.7m |
| AMERIPRISE FINANCIAL INC | Sold out | -1.6m |
Biggest calls
| JANE STREET GROUP, LLC | New | $372.3k170.0k shares |
| CITADEL ADVISORS LLC | Reduced | $161.6k73.8k shares |
| GROUP ONE TRADING LLC | Added | $133.8k61.1k shares |
| Blue Owl Capital Holdings LP | Reduced | $106.3k303.8k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $71.4k32.6k shares |
| SIMPLEX TRADING, LLC | Added | $58.3k26.6k shares |
Biggest puts
| CITADEL ADVISORS LLC | Reduced | $143.4k65.5k shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $123.1k56.2k shares |
| GROUP ONE TRADING LLC | Added | $37.0k16.9k shares |
| SIMPLEX TRADING, LLC | Reduced | $13.6k6.2k 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 |
|---|---|
| TANG CAPITAL MANAGEMENT LLC 13G · passive investor no change · filed 2025-11-14 | 10.0% |
ORBIMED ADVISORS LLC
13D · may seek influence
-2.1 pts · filed 2025-08-15
Stated purposeThe Reporting Persons from time to time intend to review their investment in the Issuer on the basis of various factors, including the Issuer's business, financial condition, results of operations and prospects, general economic and industry conditions, the securities markets in general and those for the Issuer's Shares in particular, as well as other developments and other investment opportunities. Based upon such review, the Reporting Persons will take such actions in the future as the Reporting Persons may deem appropriate in light of the circumstances existing from time to time. If the Reporting Persons believe that further investment in the Issuer is attractive, whether because of the market price of Shares or otherwise, they may acquire Shares or other securities of the Issuer either… Full filing |
8.9% |
| SUVRETTA CAPITAL MANAGEMENT, LLC 13G · passive investor +3.0 pts · filed 2025-08-21 | 8.2% |
| STATE STREET CORP 13G · institution new · filed 2026-08-07 | 5.5% |
| BlackRock, Inc. 13G · institution +0.6 pts · filed 2026-01-21 | 5.2% |
Fell to 5% or below in the last year: Vivo Opportunity Fund Holdings, L.P. (4.0%, 2026-08-14), BIOTECHNOLOGY VALUE FUND L P (4.3%, 2026-05-15), Blackstone Holdings II L.P. (3.4%, 2026-02-13)
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 | — | 0 | — | — |
| Q1 2025 | 0 | — | 0 | — | — |
| Q2 2025 | 3 | $80.3k | 2 | $5.7m | — |
| Q3 2025 | 0 | — | 0 | — | — |
| Q4 2025 | 0 | — | 0 | — | — |
| Q1 2026 | 0 | — | 0 | — | — |
| Q2 2026 | 2 | $75.6k | 0 | — | — |
| Q3 2026 | 1 | $2.8k | 0 | — | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-09-24 | Lerner Neil Chief Accounting Officer | Bought | $2.8k2.5k shares |
| 2026-04-29 | Anderman Jonathan General Counsel | Bought | $47.2k25.0k shares |
| 2026-04-29 | Lerner Neil Chief Accounting Officer | Bought | $28.4k15.0k 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 |
|---|---|---|
| TANG CAPITAL MANAGEMENT LLC 1.79% of their portfolio | 18.0m $39.4m | Added +1.2m |
| ORBIMED ADVISORS LLC 0.63% of their portfolio | 15.2m $33.3m | Unchanged |
| MONTANOVA CAPITAL, LLC 0.65% of their portfolio | 14.1m $30.9m | Reduced -206.2k |
| BlackRock, Inc. 0.00% of their portfolio | 11.3m $24.7m | Added +1.8m |
| STATE STREET CORP 0.00% of their portfolio | 10.0m $21.8m | Added +3.3m |
| ENAVATE SCIENCES GP, LLC 4.94% of their portfolio | 7.8m $17.1m | Unchanged |
| Vivo Capital, LLC 1.55% of their portfolio | 7.8m $17.0m | Reduced -1.8m |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 6.1m $13.4m | Added +81.6k |
| Palo Alto Investors LP 1.76% of their portfolio | 5.8m $12.8m | Added +4.3m |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 4.7m $10.3m | Added +3.9m |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 3.8m $8.4m | Added +249.4k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 3.8m $8.3m | Added +2.7m |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 3.7m $8.1m | Added +1.1m |
| Blue Owl Capital Holdings LP 1.21% of their portfolio | 3.6m $7.9m | Added +682.6k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 3.6m $7.8m | Added +2.8m |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 3.5m $7.7m | Added +1.5m |
| Rock Springs Capital Management LP 0.38% of their portfolio | 3.5m $7.7m | Added +219.6k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 3.5m $7.7m | Added +3.3m |
| Birchview Capital, LP 1.72% of their portfolio | 1.7m $3.7m | Added +209.1k |
| KINGDON CAPITAL MANAGEMENT, L.L.C. 0.41% of their portfolio | 1.4m $3.1m | New |
| Fisher Asset Management, LLC 0.00% of their portfolio | 1.4m $3.0m | Added +43.6k |
| ROYCE & ASSOCIATES LP 0.02% of their portfolio | 1.3m $2.9m | Reduced -283.0k |
| FMR LLC 0.00% of their portfolio | 1.2m $2.7m | Reduced -589.5k |
| ADAGE CAPITAL PARTNERS GP, L.L.C. 0.00% of their portfolio | 1.2m $2.6m | Reduced -7.3m |
| ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio | 1.2m $2.5m | New |
| NORTHERN TRUST CORP 0.00% of their portfolio | 1.1m $2.5m | Added +92.4k |
| Atle Fund Management AB 0.62% of their portfolio | 1.0m $2.3m | Added +1.0m |
| Nuveen, LLC 0.00% of their portfolio | 1.0m $2.2m | Added +719.6k |
| Squarepoint Ops LLC 0.00% of their portfolio | 1.0m $2.2m | Added +957.3k |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 1.0m $2.2m | Added +2.8k |
| Blackstone Inc. 0.01% of their portfolio | 899.9k $2.0m | Reduced -957.9k |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 807.0k $1.8m | New |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 789.4k $1.7m | Reduced -58.3k |
| KVP Capital Advisors, LP 1.24% of their portfolio | 771.0k $1.7m | Added +271.0k |
| MORGAN STANLEY 0.00% of their portfolio | 735.2k $1.6m | Added +374.8k |
| CITIGROUP INC 0.00% of their portfolio | 713.9k $1.6m | Added +115.7k |
| UBS Group AG 0.00% of their portfolio | 712.8k $1.6m | Reduced -1.7m |
| Burkehill Global Management, LP 0.06% of their portfolio | 700.0k $1.5m | Unchanged |
| Point72 Asset Management, L.P. 0.00% of their portfolio | 686.6k $1.5m | New |
| ACUTA CAPITAL PARTNERS, LLC 0.91% of their portfolio | 595.2k $1.3m | Reduced -253.9k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 566.9k $1.2m | Reduced -298.7k |
| CM Management, LLC 0.77% of their portfolio | 550.0k $1.2m | New |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 541.2k $1.2m | Added +101.4k |
| Connor, Clark & Lunn Investment Management Ltd. 0.00% of their portfolio | 523.8k $1.1m | Added +26.0k |
| Artia Global Partners LP 0.16% of their portfolio | 383.2k $839.2k | New |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 378.7k $829.3k | Added +18.6k |
| ArrowMark Colorado Holdings LLC 0.03% of their portfolio | 364.7k $798.8k | Reduced -150.1k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 351.0k $768.8k | Added +53.7k |
| MARSHALL WACE, LLP 0.00% of their portfolio | 334.9k $733.4k | New |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 320.3k $701.5k | Added +287.2k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 308.3k $675.2k | Added +151.3k |
| ALGERT GLOBAL LLC 0.01% of their portfolio | 308.1k $674.8k | Added +271.3k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 303.1k $663.9k | Reduced -67.9k |
| NATIXIS 0.00% of their portfolio | 297.7k $652.0k | New |
| Exome Asset Management LLC 0.37% of their portfolio | 276.2k $604.8k | New |
| Caption Management, LLC 0.02% of their portfolio | 263.6k $577.2k | New |
| DV EQUITIES, LLC 0.07% of their portfolio | 233.1k $510.4k | First filing |
| Seven Fleet Capital Management LP 0.08% of their portfolio | 233.1k $510.4k | Reduced -707.5k |
| PANAGORA ASSET MANAGEMENT INC 0.00% of their portfolio | 222.2k $486.6k | New |
| XTX Topco Ltd 0.01% of their portfolio | 217.5k $476.3k | Added +147.4k |
| Orion Porfolio Solutions, LLC 0.00% of their portfolio | 213.9k $468.4k | New |
| D. E. Shaw & Co., Inc. 0.00% of their portfolio | 204.5k $447.8k | Added +138.5k |
| Rafferty Asset Management, LLC 0.00% of their portfolio | 190.1k $416.4k | Reduced -5.7k |
| Creative Planning 0.00% of their portfolio | 182.8k $400.4k | Added +76.7k |
| ALPS ADVISORS INC 0.00% of their portfolio | 182.8k $400.3k | Added +36.2k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 177.8k $389.4k | Added +38.2k |
| Mariner, LLC 0.00% of their portfolio | 172.8k $378.4k | New |
| Swiss National Bank 0.00% of their portfolio | 171.7k $376.0k | Reduced -49.0k |
| HRT FINANCIAL LP 0.00% of their portfolio | 170.1k $372.0k | Added +150.3k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 161.9k $856.3k | Added +77.9k |
| Virtus Investment Advisers, LLC 0.08% of their portfolio | 161.2k $353.0k | Added +108.3k |
| CANADA PENSION PLAN INVESTMENT BOARD 0.00% of their portfolio | 160.9k $352.4k | Added +135.8k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 158.4k $347.0k | Added +11.4k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 134.3k $294.2k | Added +998 |
| IEQ CAPITAL, LLC 0.00% of their portfolio | 122.9k $269.3k | New |
| ADAR1 Capital Management, LLC 0.01% of their portfolio | 122.1k $267.5k | Reduced -16.9k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 109.8k $240.4k | Added +62.1k |
| Quadrature Capital Ltd 0.00% of their portfolio | 108.2k $237.1k | Added +94.4k |
| MERCER GLOBAL ADVISORS INC /ADV 0.00% of their portfolio | 106.6k $233.4k | New |
| LOS ANGELES CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 105.1k $230.2k | New |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 104.3k $229.0k | Added +4.7k |
| PROFUND ADVISORS LLC 0.01% of their portfolio | 95.2k $208.5k | Added +7.5k |
| Schonfeld Strategic Advisors LLC 0.00% of their portfolio | 92.2k $202.0k | Reduced -983.8k |
| TUDOR INVESTMENT CORP ET AL 0.00% of their portfolio | 90.0k $197.2k | Added +1.1k |
| Jain Global LLC 0.00% of their portfolio | 88.3k $193.4k | New |
| SmartHarvest Portfolios, LLC 0.06% of their portfolio | 86.5k $189.5k | Added +51.8k |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC 0.00% of their portfolio | 83.6k $194.7k | New |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 82.5k $179.9k | Added +8.4k |
| GROUP ONE TRADING LLC 0.01% of their portfolio | 81.6k $178.6k | Added +51.3k |
| Cerity Partners LLC 0.00% of their portfolio | 81.0k $177.3k | New |
| OPTIMIZE FINANCIAL INC. 0.06% of their portfolio | 80.2k $175.6k | Reduced -279 |
| Sound Capital Solutions LLC 0.04% of their portfolio | 80.2k $175.6k | First filing |
| SG Americas Securities, LLC 0.00% of their portfolio | 76.4k $167.0k | Added +28.7k |
| Legal & General Group Plc 0.00% of their portfolio | 75.1k $164.5k | Unchanged |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 74.7k $163.6k | Unchanged |
| MetLife Investment Management, LLC 0.00% of their portfolio | 71.4k $156.4k | Added +7.2k |
| GSA CAPITAL PARTNERS LLP 0.01% of their portfolio | 70.2k $154.0k | New |
| Invesco Ltd. 0.00% of their portfolio | 69.8k $152.9k | Reduced -31.4k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 68.2k $149.4k | Added +751 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 67.7k $148.3k | Reduced -44.6k |