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Equibles

MBX

MBX Biosciences, Inc.

Company with tickers: MBX

CIK
1776111
CUSIP
55287L101
Shares Outstanding
47,597,536
13F Activity (30d)
115 filings 109 filers

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 158
Total Value: $1,573,265,740
Total Shares: 52,705,723
Showing 1–100 of 162 holdings by value · page 1 of 2

Institutional Ownership Trend

7 quarters

Holder Concentration

Across 158 13F filers · Δ vs Dec 31, 2025
Top Holder
12.6%
Sep 2024 → Mar 2026 · range 12.6% – 19.8%
−1.0 pts
Top 5
38.0%
Sep 2024 → Mar 2026 · range 38.0% – 63.9%
−4.5 pts
Top 10
58.8%
Sep 2024 → Mar 2026 · range 58.8% – 87.0%
−5.0 pts
HHI
470
Sep 2024 → Mar 2026 · range 470 – 1,018
Broadly held −65

Quarterly Activity

vs Dec 31, 2025
New
39
Increased
43
Decreased
48
Sold Out
21
Unchanged
28
Holder count: +18
Institutional value: +1.9%
Shares held: +7.7%

Top Buyers

vs Dec 31, 2025
Institution Added Now Holds Open
Mega FMR LLC +2,920,938 2,936,684
Mid Aaron Wealth Advisors LLC +1,098,176 1,168,176
Mid BRAIDWELL LP +473,867 1,492,467
Small STEMPOINT CAPITAL LP +420,916 499,469
Mega PRICE T ROWE ASSOCIATES INC /MD/ +188,501 1,029,007

Top Sellers

vs Dec 31, 2025
Institution Sold Now Holds Open
Mid EcoR1 Capital, LLC −1,346,604 777,000
Mid Deep Track Capital, LP −492,221 2,757,569
Large Driehaus Capital Management LLC −389,947 1,018,212
Mega D. E. Shaw & Co., Inc. −382,949 288,889
Mid ORBIMED ADVISORS LLC −297,316 3,637,887

Top New Positions

vs Dec 31, 2025
Institution Acquired Value (USD) Open
Large Polar Capital Holdings Plc 1,622,186 $48,422,252
Mega VANGUARD CAPITAL MANAGEMENT LLC 1,477,592 $44,106,121
Mid Caligan Partners LP 848,590 $25,330,411
Large Candriam S.C.A. 294,374 $8,787,063
Mega VANGUARD PORTFOLIO MANAGEMENT LLC 293,295 $8,754,855

Top Sold-Out Positions

vs Dec 31, 2025
Institution Previously Held Last Value (USD) Open
Mega VANGUARD GROUP INC 1,817,811 $57,333,757
Large Point72 Asset Management, L.P. 680,609 $21,466,407
Small Trails Edge Capital Partners, LP 315,158 $9,940,083
Mid 683 Capital Management, LLC 158,800 $5,008,552
Large Balyasny Asset Management L.P. 119,726 $3,776,158
Filter: New 39 Increased 43 Reduced 48 Sold out 21 Unchanged 28
Showing 100 of 162
All Common Calls Puts
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Holder Value (USD) % of 13F Shares Open
Mid Frazier Life Sciences Management, L.P. $198,562,588 12.62% 6,652,013
Mid ORBIMED ADVISORS LLC $108,590,926 6.90% 3,637,887
Mid NEA Management Company, LLC $107,892,407 6.86% 3,614,486
Mega WELLINGTON MANAGEMENT GROUP LLP $95,275,943 6.06% 3,191,824
Mega BlackRock, Inc. $87,800,964 5.58% 2,941,406
Mega FMR LLC $87,660,017 5.57% 2,936,684
Mid Deep Track Capital, LP $82,313,434 5.23% 2,757,569
Small NVP ASSOCIATES, LLC $63,769,599 4.05% 2,136,335
Large Polar Capital Holdings Plc $48,422,252 3.08% 1,622,186
Mid BRAIDWELL LP $44,550,139 2.83% 1,492,467
Mega VANGUARD CAPITAL MANAGEMENT LLC $44,106,121 2.80% 1,477,592
Mid Aaron Wealth Advisors LLC $34,870,053 2.22% 1,168,176
Mid Cormorant Asset Management, LP $33,432,000 2.13% 1,120,000
Mega PRICE T ROWE ASSOCIATES INC /MD/ $30,715,858 1.95% 1,029,007
Large Driehaus Capital Management LLC $30,393,628 1.93% 1,018,212
Mid Kynam Capital Management, LP $27,903,750 1.77% 934,799
Mega CITADEL ADVISORS LLC $27,845,064 1.77% 932,833
Large Woodline Partners LP $26,866,880 1.71% 900,063
Mid EVENTIDE ASSET MANAGEMENT, LLC $26,566,500 1.69% 890,000
Mid Caligan Partners LP $25,330,411 1.61% 848,590
Small Parkman Healthcare Partners LLC $23,881,104 1.52% 800,037
Mega STATE STREET CORP $23,498,158 1.49% 787,208
Mid EcoR1 Capital, LLC $23,193,450 1.47% 777,000
Mega GEODE CAPITAL MANAGEMENT, LLC $20,010,991 1.27% 670,385
Mid TCG Crossover Management, LLC $19,402,500 1.23% 650,000
Mega MILLENNIUM MANAGEMENT LLC $16,847,787 1.07% 564,415
Small STEMPOINT CAPITAL LP $14,909,149 0.95% 499,469
Mega GOLDMAN SACHS GROUP INC $13,669,658 0.87% 457,945
Mega UBS Group AG $10,355,381 0.66% 346,914
Large Candriam S.C.A. $8,787,063 0.56% 294,374
Mega VANGUARD PORTFOLIO MANAGEMENT LLC $8,754,855 0.56% 293,295
Mega D. E. Shaw & Co., Inc. $8,623,336 0.55% 288,889
Mid Rock Springs Capital Management LP $8,595,814 0.55% 287,967
Small Opaleye Management Inc. $7,761,000 0.49% 260,000
Mega CHARLES SCHWAB INVESTMENT MANAGEMENT INC $6,415,003 0.41% 214,908
Small Elmind Capital, LP $6,298,350 0.40% 211,000
Mega NORTHERN TRUST CORP Bank $6,285,662 0.40% 210,575
Mid BOOTHBAY FUND MANAGEMENT, LLC $6,210,262 0.39% 208,049
Mid Soleus Capital Management, L.P. $5,340,075 0.34% 178,897
Small DAFNA Capital Management LLC $5,237,630 0.33% 175,465
Mega VANGUARD FIDUCIARY TRUST CO Bank $5,079,096 0.32% 170,154
Mid Goelzer Investment Management, Inc. $4,900,534 0.31% 164,172
Mid Affinity Asset Advisors, LLC $4,477,500 0.28% 150,000
Mega JPMORGAN CHASE & CO $4,389,651 0.28% 147,057
Small Tetragon Partners GP Ltd $4,342,578 0.28% 145,480
Large Schonfeld Strategic Advisors LLC $3,695,847 0.23% 123,814
Small KVP Capital Advisors, LP $3,627,491 0.23% 121,524
Mega TD Asset Management Inc $3,462,540 0.22% 115,998
Mega TWO SIGMA INVESTMENTS, LP $3,434,988 0.22% 115,075
Mid Burkehill Global Management, LP $2,985,000 0.19% 100,000
Large Squarepoint Ops LLC $2,901,867 0.18% 97,215
Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP $2,773,065 0.18% 92,900
Mega MANUFACTURERS LIFE INSURANCE COMPANY, THE Insurance $2,705,424 0.17% 90,634
Mega Nuveen, LLC $2,441,490 0.16% 81,792
Mega Bank of New York Mellon Corp Bank $2,394,626 0.15% 80,222
Small PFM Health Sciences, LP $2,146,035 0.14% 71,894
Mega VICTORY CAPITAL MANAGEMENT INC $2,120,185 0.13% 71,028
Large MARSHALL WACE, LLP $1,871,684 0.12% 62,703
Mega SCHRODER INVESTMENT MANAGEMENT GROUP $1,711,061 0.11% 57,322
Mid XTX Topco Ltd $1,588,318 0.10% 53,210
Mega DIMENSIONAL FUND ADVISORS LP $1,395,576 0.09% 46,753
Mega Swiss National Bank Bank $1,325,340 0.08% 44,400
Small PLATINUM INVESTMENT MANAGEMENT LTD $1,301,370 0.08% 43,597
Large ALPS ADVISORS INC $1,091,017 0.07% 36,550
Mid ALGERT GLOBAL LLC $1,075,197 0.07% 36,020
Large Creative Planning $1,073,704 0.07% 35,970
Mid EXCHANGE TRADED CONCEPTS, LLC $1,022,780 0.07% 34,264
Mega RHUMBLINE ADVISERS $1,011,049 0.06% 33,871
Mega MORGAN STANLEY $942,124 0.06% 31,562
Mega ALLIANCEBERNSTEIN L.P. $910,425 0.06% 30,500
Mega BANK OF AMERICA CORP /DE/ Bank $858,187 0.05% 28,750
Large ExodusPoint Capital Management, LP $838,396 0.05% 28,087
Mega Invesco Ltd. $821,619 0.05% 27,525
Mega AQR CAPITAL MANAGEMENT LLC $817,500 0.05% 27,387
Mega CITADEL ADVISORS LLC $755,205 0.05% 25,300
Mega DEUTSCHE BANK AG\ Bank $685,057 0.04% 22,950
Large CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM Pension $679,535 0.04% 22,765
Mega JANE STREET GROUP, LLC $650,730 0.04% 21,800
Large Cerity Partners LLC $631,715 0.04% 21,163
Mega JANE STREET GROUP, LLC $597,000 0.04% 20,000
Mega Legal & General Group Plc $577,835 0.04% 19,358
Large STATE OF WISCONSIN INVESTMENT BOARD $574,970 0.04% 19,262
Micro Koa Wealth Management, LLC $534,703 0.03% 17,913
Mid Engineers Gate Manager LP $518,793 0.03% 17,380
Large Qube Research & Technologies Ltd $513,031 0.03% 17,187
Mega Vanguard Global Advisers, LLC $478,435 0.03% 16,028
Large MetLife Investment Management, LLC $478,137 0.03% 16,018
Mega VANGUARD ASSET MANAGEMENT, Ltd $440,347 0.03% 14,752
Small Optimize Financial Inc $433,063 0.03% 14,508
Mega CITIGROUP INC $402,944 0.03% 13,499
Large MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. Mutual Fund $397,751 0.03% 13,325
Mid Jump Financial, LLC $379,095 0.02% 12,700
Large Swiss Life Asset Management Ltd $362,080 0.02% 12,130
Mega BARCLAYS PLC $353,363 0.02% 11,838
Small HighVista Strategies LLC $342,439 0.02% 11,472
Mega CANADA PENSION PLAN INVESTMENT BOARD Pension $325,365 0.02% 10,900
Mega WELLS FARGO & COMPANY/MN $321,245 0.02% 10,762
Mega BNP PARIBAS ARBITRAGE, SA $309,962 0.02% 10,384
Mega JANUS HENDERSON GROUP PLC $307,455 0.02% 10,300
Large Verition Fund Management LLC $305,126 0.02% 10,222

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