JY
MBX

Jeff Yass’s MBX Biosciences MBX Stock Holding History

Jeff Yass’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 		$1.71M Buy
+31,000
New +$1.08M ﹤0.01% 6842
2026
Q1 		– Sell
-228,000
Closed -$7.19M – 14359
2025
Q4 		$7.19M Sell
228,000
-258,800
-53% -$6.28M ﹤0.01% 3493
2025
Q3 		$8.52M Buy
486,800
+430,200
+760% +$5.75M ﹤0.01% 3251
2025
Q2 		$646K Buy
+56,600
New +$577K ﹤0.01% 8576

Other funds holding MBX

FLSM
Frazier Life Sciences Management Palo Alto, California $4.59B AUM 237.58% 1-Year Est. Return
Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 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

Jeff Yass's MBX Position: Q2 2026 in Review

Jeff Yass increased its MBX Biosciences (MBX) stake by 181% in Q2 2026, buying an estimated $601K and bringing the position to 26,684 shares worth $1.47M. The position accounts for ﹤0.01% of the portfolio, ranked #7212.

Jeff Yass first reported a position in MBX in Q1 2025 and has held it in 5 quarters since. The position peaked at $2.41M in Q4 2025. 171 funds tracked by Wall St. Rank hold MBX as of Q2 2026.

  • Jeff Yass held 26,684 shares of MBX Biosciences worth $1.47M as of Q2 2026.
  • Jeff Yass bought 17,197 MBX Biosciences shares in Q2 2026, an estimated $601K.
  • MBX Biosciences made up ﹤0.01% of Jeff Yass's portfolio in Q2 2026, its #7212 holding.
  • Jeff Yass first reported a position in MBX Biosciences in Q1 2025 and has held it in 5 quarters since.
  • Jeff Yass's MBX Biosciences position peaked at $2.41M in Q4 2025.
  • 171 funds tracked by Wall St. Rank held MBX Biosciences as of Q2 2026.

Based on Susquehanna International Group's 13F filing for Q2 2026, filed 14 Aug 2026.