Upstream Bio UPB Institutional Ownership

NASDAQ UPB

$2.80 -0.02 (-0.71%)

At close: Oct 21, 2026 · 4:00 PM EDT

Institutions by Trading Activity

149 Institutions

Increased 102 68.5%

Unchanged 19 12.8%

Reduced 28 18.8%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

92.34%

▲+10.30 pp QoQ

Shares Held by Institutions

50.58Mn

of 54.77Mn outstanding

▲+13.29% QoQ

Shares Outstanding

54.77Mn

4.19Mn held outside 13F filers

Institutional Investors

149

filed 13F for Jun 2026

▲+10 vs prior quarter

Net Shares Added (QoQ)

+5.93Mn

accumulated since last quarter

Value of Holdings

$142.63Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 11, 2026

Upstream Bio, Inc. (NASDAQ:UPB) counted 149 institutional investors among its 13F-reported shareholders for the quarter ended June 30, 2026.

These investors held 92.34% of outstanding shares in Q2 2026, up from 82.04% the quarter before.
Total shares held in Upstream Bio rose 13.29% versus Q1 2026, while the number of holders rose 83.95% versus Q2 2025.
Of the 149 holders, 102 added to their positions, 28 reduced their stakes and 19 left their positions unchanged in Q2 2026.
Institutional investors held 50.58Mn shares of Upstream Bio in total at the end of Q2 2026, up 5.93Mn from the prior quarter and up 2.32Mn from a year earlier.
FMR LLC held the largest position in UPB at 8.16Mn shares as of June 30, 2026, or 14.90% of shares outstanding.
The largest position increases in UPB for Q2 2026 were by JPMorgan Chase & Co (+549.04K shares), AQR Capital Management LLC (+472.7K shares), BNP Paribas Financial Markets (+385.55K shares), BlackRock, Inc. (+382.67K shares) and Qube Research & Technologies Ltd (+359.18K shares).
On the other side, among holders that kept a position in Upstream Bio, the largest reductions in Q2 2026 came from HSBC Holdings PLC (-629.53K shares), Samsara BioCapital, LLC (-382.33K shares), Y-Intercept (Hong Kong) Ltd (-307.08K shares), Bain Capital Life Sciences Investors, LLC (-266.26K shares) and Sphera Funds Management LTD. (-138.3K shares).
According to Business Quant data, the leading holders of UPB for Q2 2026 were FMR LLC (8.16Mn shares), OrbiMed Advisors LLC (5.69Mn shares), Norges Bank (3.77Mn shares), BlackRock, Inc. (3.75Mn shares), Decheng Capital LLC (2.72Mn shares), Enavate Sciences GP, LLC (2.46Mn shares), Vanguard Capital Management LLC (1.88Mn shares), Millennium Management LLC (1.14Mn shares), D. E. Shaw & Co., Inc. (1.04Mn shares) and JPMorgan Chase & Co (1.01Mn shares).

Form 13F Holdings

149 Institutional Holders

Report period 30 Jun, 2026

Total shares held 50.58Mn

Of outstanding 92.34%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	FMR LLC	0000315066	8,162,897	14.90%	▲61,334	+0.76%	$56.49Mn
2	ORBIMED ADVISORS LLC	0001055951	5,693,589	10.40%	0	0.00%	$39.40Mn
3	NORGES BANK	0001374170	3,768,619	6.88%	▲3,768,619	0.00%	$26.08Mn
4	BlackRock, Inc.	0002012383	3,753,358	6.85%	▲382,669	+11.35%	$25.97Mn
5	Decheng Capital LLC	0002010850	2,724,868	4.98%	0	0.00%	$18.86Mn
6	Enavate Sciences GP, LLC	0001953107	2,459,703	4.49%	0	0.00%	$17.02Mn
7	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	1,876,734	3.43%	▲3,160	+0.17%	$12.99Mn
8	MILLENNIUM MANAGEMENT LLC	0001273087	1,143,775	2.09%	▲206,452	+22.03%	$7.91Mn
9	D. E. Shaw & Co., Inc.	0001009207	1,036,044	1.89%	▲215,564	+26.27%	$7.17Mn
10	Jpmorgan Chase & Co	0000019617	1,012,044	1.85%	▲549,043	+118.58%	$7.01Mn
11	Qube Research & Technologies Ltd	0001729829	978,500	1.79%	▲359,179	+58.00%	$6.77Mn
12	Parkman Healthcare Partners LLC	0001777015	935,247	1.71%	▲148,464	+18.87%	$6.47Mn
13	GEODE CAPITAL MANAGEMENT, LLC	0001214717	931,261	1.70%	▼19,356	-2.04%	$6.45Mn
14	SEB Asset Management AB	0002127509	878,473	1.60%	0	0.00%	$6.08Mn
15	Woodline Partners LP	0001784547	831,481	1.52%	0	0.00%	$5.75Mn
16	State Street Corp	0000093751	766,323	1.40%	▲60,973	+8.64%	$5.30Mn
17	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	712,667	1.30%	▼15,044	-2.07%	$4.93Mn
18	Y-Intercept (Hong Kong) Ltd	0001772875	693,555	1.27%	▼307,076	-30.69%	$4.80Mn
19	Bain Capital Life Sciences Investors, LLC	0001703031	600,949	1.10%	▼266,262	-30.70%	$4.16Mn
20	AQR CAPITAL MANAGEMENT LLC	0001167557	544,869	0.99%	▲472,698	+654.97%	$3.77Mn

Showing 1 to 20 of 149 holders