Latest Period
Q2 2026
Security Snapshot
MBX Biosciences, Inc. - Common Stock, $0.0001 par value per share (MBX) Institutional Ownership
CUSIP: 55287L101
13F Institutional Holders and Ownership History from Q3 2024 to Q2 2026
Institutions Reporting
172
Shares (Excl. Options)
55,478,880
Price
$55.20
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- Security type / class
- Equity / Common Stock, $0.0001 par value per share
- Symbol
- MBX on Nasdaq
- All holders as of 30 Jun 2026
- Q2 2026
- Total 13F shares
- 55,478,880
- Total 13F value
- $3,061,454,995
- Portfolio coverage rank
- 0%
- Share change
- +2,943,009
- Value change
- +$207,879,740
- Number of holders
- 172
- Shares outstanding
- 47,598,049
- SEC-reported price per share
- $64.41
- Insider filing price
- $64.41
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
3 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- MBX - MBX Biosciences, Inc. - Common Stock, $0.0001 par value per share is tracked under CUSIP 55287L101.
- 172 institutions reported positions in Q2 2026.
- 11 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 155 to 172 between Q1 2026 and Q2 2026.
- SEC-reported value moved from $1,567,289,653 to $3,061,454,995.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 172 institutions filings for Q2 2026.
Security key
55287L101
Latest holder period
Q2 2026
13F holders
172
13D/G owners
11
CIK / CUSIP context first
Open Q2 2026 holders
MBX full holder history
MBX Biosciences, Inc. SEC filings
MBX Biosciences, Inc. company facts
MBX Biosciences, Inc. insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 55287L101:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
11
Security
MBX
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| FMR LLC | 11% | +83% | $293,826,960 | +$131,719,966 | 5,322,885 | +81% | FMR LLC | 30 Jun 2026 |
| Frazier Life Sciences Public Fund, L.P. | 12% | 0% | $323,728,813 | +$1,193,187 | 5,243,421 | +0.37% | Patrick J. Heron | 06 Aug 2026 |
| WELLINGTON MANAGEMENT GROUP LLP | 10% | +38% | $274,762,754 | +$89,842,562 | 4,977,523 | +49% | Wellington Management Group LLP | 30 Jun 2026 |
| New Enterprise Associates 17, L.P. | 8.1% | $63,340,795 | 3,619,474 | Edward T. Mathers | 06 Nov 2025 | |||
| ORBIMED ADVISORS LLC | 6.4% | -16% | $189,841,424 | -$34,761,719 | 3,074,853 | -15% | ORBIMED ADVISORS LLC | 06 Aug 2026 |
| BlackRock, Inc. | 5.5% | +14% | $145,075,854 | +$18,805,791 | 2,628,181 | +15% | BlackRock, Inc. | 30 Jun 2026 |
| Paradigm Biocapital Advisors LP | 5.2% | $78,355,461 | 2,493,015 | Paradigm BioCapital Advisors LP | 16 Jun 2026 | |||
| Norwest Venture Partners XVI, LP | 4.8% | $29,738,337 | 2,140,989 | Tiba Aynechi | 26 Sep 2025 | |||
| Wellington Biomedical Innovation Master Investors (Cayman) II L.P. | 4.5% | $35,304,395 | 2,017,394 | Wellington Biomedical Innovation Master Investors (Cayman) II, L.P. | 30 Sep 2025 | |||
| Hawryluk P. Kent | 4.3% | $34,925,782 | 1,995,759 | P. Kent Hawryluk | 30 Sep 2025 | |||
| Deep Track Capital, LP | 3.6% | -42% | $106,968,810 | -$28,154,860 | 1,732,569 | -21% | Deep Track Capital, LP | 30 Jun 2026 |
As of 30 Jun 2026, 172 institutional investors reported holding 55,478,880 shares of MBX Biosciences, Inc. - Common Stock, $0.0001 par value per share (MBX). This represents 117% of the company’s total 47,598,049 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
101%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| Frazier Life Sciences Management, L.P. | 14% | 6,652,013 | 0% | 8% | $367,191,118 |
| FMR LLC | 11% | 5,322,885 | +81% | 0.01% | $293,823,234 |
| WELLINGTON MANAGEMENT GROUP LLP | 10% | 4,977,523 | +56% | 0.05% | $274,759,269 |
| NEA Management Company, LLC | 7.6% | 3,614,486 | 0% | 13% | $199,519,627 |
| ORBIMED ADVISORS LLC | 7.2% | 3,428,736 | -5.7% | 3.6% | $189,266,227 |
| BlackRock, Inc. | 7% | 3,323,672 | +13% | 0% | $183,466,695 |
| Paradigm Biocapital Advisors LP | 5.3% | 2,508,015 | 2.6% | $138,442,428 | |
| NVP ASSOCIATES, LLC | 4.5% | 2,136,335 | 0% | 36% | $117,925,692 |
| Deep Track Capital, LP | 3.6% | 1,732,569 | -37% | 1.4% | $95,637,809 |
| Polar Capital Holdings Plc | 3.4% | 1,608,514 | -0.84% | 0.25% | $88,789,973 |
| VANGUARD CAPITAL MANAGEMENT LLC | 3.1% | 1,477,388 | -0.01% | 0% | $81,551,818 |
| Aaron Wealth Advisors LLC | 2.5% | 1,167,799 | -0.03% | 3.3% | $64,462,505 |
| Driehaus Capital Management LLC | 2.2% | 1,056,579 | +3.8% | 0.34% | $58,323,161 |
| Kynam Capital Management, LP | 2% | 934,799 | 0% | 2.9% | $51,600,905 |
| Woodline Partners LP | 1.9% | 900,092 | +0% | 0.15% | $49,685,078 |
| EVENTIDE ASSET MANAGEMENT, LLC | 1.8% | 873,492 | -1.9% | 0.64% | $48,216,758 |
| STATE STREET CORP | 1.8% | 864,466 | +9.8% | 0% | $47,718,523 |
| PRICE T ROWE ASSOCIATES INC /MD/ | 1.7% | 814,807 | -21% | 0% | $44,978,000 |
| Parkman Healthcare Partners LLC | 1.7% | 800,173 | +0.02% | 4.5% | $44,169,550 |
| GEODE CAPITAL MANAGEMENT, LLC | 1.6% | 773,072 | +15% | 0% | $42,683,039 |
| BRAIDWELL LP | 1.5% | 710,880 | -52% | 1.5% | $39,240,576 |
| TCG Crossover Management, LLC | 1.4% | 650,000 | 0% | 0.86% | $35,880,000 |
| Cormorant Asset Management, LP | 1.2% | 550,000 | -51% | 1.6% | $30,360,000 |
| Soleus Capital Management, L.P. | 1.1% | 515,279 | +188% | 0.98% | $28,443,401 |
| GOLDMAN SACHS GROUP INC | 0.96% | 459,005 | +0.23% | 0% | $25,337,076 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
8
Latest
Q2 2026
Rows shown
1-8 of 8
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q2 | 55,478,880 | $3,061,454,995 | +$207,879,740 | $55.20 | 172 |
| 2026 Q1 | 52,523,690 | $1,567,289,653 | +$114,687,638 | $29.85 | 155 |
| 2025 Q4 | 48,428,720 | $1,527,258,385 | +$34,720,034 | $31.54 | 138 |
| 2025 Q3 | 47,790,065 | $836,364,494 | +$203,956,820 | $17.50 | 117 |
| 2025 Q2 | 36,839,365 | $420,338,016 | +$15,667,999 | $11.41 | 87 |
| 2025 Q1 | 35,666,401 | $263,219,997 | +$14,436,597 | $7.38 | 79 |
| 2024 Q4 | 32,941,714 | $606,485,118 | +$45,787,522 | $18.43 | 63 |
| 2024 Q3 | 30,305,441 | $784,071,713 | +$784,024,689 | $25.98 | 45 |