ACM
UPB

ADAR1 Capital Management’s Upstream Bio Inc UPB Stock Holding History

ADAR1 Capital Management’s Portfolio UPB Stock Details UPB Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$315K Buy
+35,000
New +$630K 0.02% 236
2025
Q2 		– Sell
-15,000
Closed -$91.8K – 244
2025
Q1 		$91.8K Buy
+15,000
New +$143K 0.02% 169

Other funds holding UPB

Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
O
OrbiMed New York $5.05B AUM 125.28% 1-Year Est. Return
BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
DC
Decheng Capital Menlo Park, California $661M AUM 299.97% 1-Year Est. Return
ES
Enavate Sciences Menlo Park, California $352M AUM 220.14% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
YIH
Y-Intercept (HK) Hong Kong $5.05B AUM 17.89% 1-Year Est. Return
Federated Hermes
Federated Hermes Pittsburgh, Pennsylvania $61.5B AUM 30.7% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
Millennium Management
Millennium Management New York $240B AUM 35.51% 1-Year Est. Return

ADAR1 Capital Management's UPB Position: Q1 2026 in Review

ADAR1 Capital Management opened a new position in Upstream Bio Inc (UPB) in Q1 2026: 35,000 shares worth $315K. The stake represents 0.02% of the portfolio and ranks #236 among its holdings. This is a return to the name: ADAR1 Capital Management previously reported a position in UPB as recently as Q1 2025.

ADAR1 Capital Management first reported a position in UPB in Q1 2025 and has held it in 2 quarters since. 140 funds tracked by Wall St. Rank hold UPB as of Q1 2026.

  • ADAR1 Capital Management held 35,000 shares of Upstream Bio Inc worth $315K as of Q1 2026.
  • Upstream Bio Inc was a new ADAR1 Capital Management position in Q1 2026.
  • Upstream Bio Inc made up 0.02% of ADAR1 Capital Management's portfolio in Q1 2026, its #236 holding.
  • ADAR1 Capital Management first reported a position in Upstream Bio Inc in Q1 2025 and has held it in 2 quarters since.
  • 140 funds tracked by Wall St. Rank held Upstream Bio Inc as of Q1 2026.

Based on ADAR1 Capital Management's 13F filing for Q1 2026, filed 18 May 2026.