Fidelity Investments
MBX

Fidelity Investments’s MBX Biosciences MBX Stock Holding History

Fidelity Investments’s Portfolio MBX Stock Details MBX Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$294M Buy
5,322,885
+2,386,201
+81% +$83.3M 0.01% 768
2026
Q1 		$87.7M Buy
2,936,684
+2,920,938
+18,550% +$99.3M ﹤0.01% 1235
2025
Q4 		$497K Sell
15,746
-53,230
-77% -$1.29M ﹤0.01% 3086
2025
Q3 		$1.21M Buy
68,976
+7,643
+12% +$102K ﹤0.01% 2729
2025
Q2 		$700K Buy
61,333
+17,093
+39% +$174K ﹤0.01% 2843
2025
Q1 		$326K Buy
44,240
+19,667
+80% +$208K ﹤0.01% 3055
2024
Q4 		$453K Buy
+24,573
New +$524K ﹤0.01% 2970

Other funds holding MBX

FLSM
Frazier Life Sciences Management Palo Alto, California $4.59B AUM 237.58% 1-Year Est. Return
Wellington Management Group
Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return
NMC
NEA Management Company Timonium, Maryland $1.59B AUM 234.06% 1-Year Est. Return
O
OrbiMed New York $5.4B AUM 163.13% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
PBA
Paradigm Biocapital Advisors New York $5.34B AUM 380.18% 1-Year Est. Return
NA
NVP Associates Menlo Park, California $328M AUM 166.51% 1-Year Est. Return
DTC
Deep Track Capital Greenwich, Connecticut $6.87B AUM 205.24% 1-Year Est. Return
PCH
Polar Capital Holdings London, United Kingdom $42.4B AUM 181.11% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

Fidelity Investments's MBX Position: Q2 2026 in Review

Fidelity Investments increased its MBX Biosciences (MBX) stake by 81% in Q2 2026, buying an estimated $83.3M and bringing the position to 5,322,885 shares worth $294M. The position accounts for 0.01% of the portfolio, ranked #768.

Fidelity Investments first reported a position in MBX in Q4 2024 and has held it in 7 quarters since. 172 funds tracked by Wall St. Rank hold MBX as of Q2 2026.

  • Fidelity Investments held 5,322,885 shares of MBX Biosciences worth $294M as of Q2 2026.
  • Fidelity Investments bought 2,386,201 MBX Biosciences shares in Q2 2026, an estimated $83.3M.
  • MBX Biosciences made up 0.01% of Fidelity Investments's portfolio in Q2 2026, its #768 holding.
  • Fidelity Investments first reported a position in MBX Biosciences in Q4 2024 and has held it in 7 quarters since.
  • 172 funds tracked by Wall St. Rank held MBX Biosciences as of Q2 2026.

Based on Fidelity Investments's 13F filing for Q2 2026, filed 13 Aug 2026.