Vault-13

BOUNDLESS BIO INC BOLD

COM · Common Stock · CUSIP 10170A100

Company in San Diego, United States

40 institutional holders +4 vs Q1 2026
15,301,03315.3m shares reported held*
$38.3mreported value*
13 new 10 added 9 reduced 8 sold out net bought ≈ $17.0m (+6.8m shares)

* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once. Holder counts are more reliable. Implied quarter-end price ≈ $2.50.

Trends to Q2 2026

Institutional holders

Managers reporting a position, each quarter

0204060Q1 24: 44Q2 24: 48Q3 24: 56Q4 24: 56Q1 25: 55Q2 25: 45Q3 25: 35Q4 25: 36Q1 26: 36Q2 26: 4040Q1 24Q3 24Q1 25Q3 25Q1 26Q2 26
Numbers
QuarterHolders
Q1 202444
Q2 202448
Q3 202456
Q4 202456
Q1 202555
Q2 202545
Q3 202535
Q4 202536
Q1 202636
Q2 202640

Buyers vs sellers

Managers adding to or starting a position, vs cutting or selling out

Bought or addedCut or sold out
40040Q3 24: 21 bought or addedQ3 24: 20 cut or sold outQ4 24: 36 bought or addedQ4 24: 13 cut or sold outQ4 24Q1 25: 19 bought or addedQ1 25: 21 cut or sold outQ2 25: 18 bought or addedQ2 25: 40 cut or sold outQ2 25Q3 25: 8 bought or addedQ3 25: 25 cut or sold outQ4 25: 16 bought or addedQ4 25: 14 cut or sold outQ4 25Q1 26: 10 bought or addedQ1 26: 17 cut or sold outQ2 26: 23 bought or addedQ2 26: 17 cut or sold outQ2 26
Numbers
QuarterBought or addedCut or sold out
Q3 20242120
Q4 20243613
Q1 20251921
Q2 20251840
Q3 2025825
Q4 20251614
Q1 20261017
Q2 20262317

Biggest buyers

ARCH Venture Management, LLC New +2,694,095+2.7m
TANG CAPITAL MANAGEMENT LLC New +2,559,875+2.6m
ADAR1 Capital Management, LLC New +1,968,216+2.0m
Cormorant Asset Management, LP New +1,000,000+1.0m
MILLENNIUM MANAGEMENT LLC Added +378,764+378.8k
Affinity Asset Advisors, LLC New +250,000+250.0k
ACADIAN ASSET MANAGEMENT LLC Added +134,147+134.1k
HRT FINANCIAL LP New +116,288+116.3k
PRELUDE CAPITAL MANAGEMENT, LLC New +83,998+84.0k
BRIDGEWAY CAPITAL MANAGEMENT, LLC Added +77,500+77.5k

Biggest sellers

CITADEL ADVISORS LLC Reduced -1,197,082-1.2m
SECTORAL ASSET MANAGEMENT INC Sold out -678,574-678.6k
Stonepine Capital Management, LLC Reduced -443,087-443.1k
Sio Capital Management, LLC Sold out -163,679-163.7k
FMR LLC Reduced -114,400-114.4k
LANDSCAPE CAPITAL MANAGEMENT, L.L.C. Sold out -85,792-85.8k
Walleye Capital LLC Sold out -39,624-39.6k
Ensign Peak Advisors, Inc Reduced -27,665-27.7k
GSA CAPITAL PARTNERS LLP Reduced -24,471-24.5k
Squarepoint Ops LLC Sold out -16,374-16.4k

Major shareholders (over 5%)

Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.

HolderStakeChangeShares Last filed
FMR LLC 13G · institution filed 2026-02-05 12.0% 2.7m≈ $6.7m 2026-02-05
TANG CAPITAL MANAGEMENT LLC 13G · passive investor new · filed 2026-06-29 11.3% new 2.5m≈ $6.3m 2026-06-29
Hornby Zachary 13G · passive investor new · filed 2026-08-27 9.8% new 2.4m≈ $6.1m 2026-08-27
ADAR1 Capital Management, LLC 13G · institution new · filed 2026-08-14 8.8% new 2.0m≈ $4.9m 2026-08-14

Fell to 5% or below in the last year: CITADEL ADVISORS LLC (0.6%, 2026-08-14), Nextech VI GP S.A.R.L. (0.0%, 2026-02-17)

Insider purchases and sales since 1 Apr 2026

Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.

DateInsiderTradeSharesPrice ValueTheir holding
2026-08-26 TANG KEVIN +1 10% owner · See Footnote Sold 18,300 $2.97 $54.4k18.3k shares -1%
2026-07-21 TANG KEVIN +1 10% owner · See Footnote Bought 2,975 $2.44 $7.3k3.0k shares +<1%
2026-07-20 TANG KEVIN +1 10% owner · See Footnote Bought 1,623 $2.44 $4.0k1.6k shares +<1%
2026-07-17 TANG KEVIN +1 10% owner · See Footnote Bought 265 $2.44 $647265 shares +<1%
2026-07-16 TANG KEVIN +1 10% owner · See Footnote Bought 18,491 $2.44 $45.1k18.5k shares +1%
2026-07-15 TANG KEVIN +1 10% owner · See Footnote Bought 1,600 $2.44 $3.9k1.6k shares +<1%
2026-07-14 TANG KEVIN +1 10% owner · See Footnote Bought 43,878 $2.43 $106.6k43.9k shares +2%
2026-07-13 TANG KEVIN +1 10% owner · See Footnote Bought 48,211 $2.42 $116.7k48.2k shares +2%
2026-07-10 TANG KEVIN +1 10% owner · See Footnote Bought 43,367 $2.43 $105.4k43.4k shares +2%
2026-07-09 TANG KEVIN +1 10% owner · See Footnote Bought 7 $2.48 $177 shares +<1%
2026-07-08 TANG KEVIN +1 10% owner · By LP Bought 14,338 $2.46 $35.3k14.3k shares +0%
2026-07-07 TANG KEVIN +1 10% owner · By LP Bought 15,810 $2.48 $39.2k15.8k shares +1%
2026-07-06 TANG KEVIN +1 10% owner · By LP Bought 27,062 $2.49 $67.4k27.1k shares +1%
2026-07-02 TANG KEVIN +1 10% owner · By LP Bought 9,821 $2.49 $24.5k9.8k shares +<1%
2026-07-01 TANG KEVIN +1 10% owner · By LP Bought 71,612 $2.49 $178.3k71.6k shares +3%
2026-07-01 CRANDELL KEITH +4 10% owner · See footnote Sold 16,000 $2.49 $39.8k16.0k shares -100%
2026-07-01 ARCH Venture Fund IX, L.P. +7 10% owner · See footnote Sold 16,000 $2.49 $39.8k16.0k shares -100%
2026-06-30 TANG KEVIN +1 10% owner · By LP Bought 26,030 $2.54 $66.1k26.0k shares +1%
2026-06-29 TANG KEVIN +1 10% owner · By LP Bought 64,762 $2.47 $160.0k64.8k shares +3%
2026-06-26 TANG KEVIN +1 10% owner · By LP Bought 75,181 $2.55 $191.7k75.2k shares +3%
2026-06-25 TANG KEVIN +1 10% owner · By LP Bought 146,390 $2.48 $363.1k146.4k shares +6%

Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).

Holders, Q2 2026

#ManagerLocationShares Value% of their portfolioChangeShares change
1 ARCH Venture Management, LLC 0.61% of their portfolio CHICAGO, IL 2,694,0952.7m $6.7m $6.7m 0.61% New
2 FMR LLC 0.00% of their portfolio BOSTON, MA 2,581,0552.6m $6.5m $6.5m 0.00% Reduced -114.4k -114,400
3 TANG CAPITAL MANAGEMENT LLC 0.29% of their portfolio SAN DIEGO, CA 2,559,8752.6m $6.4m $6.4m 0.29% New
4 ADAR1 Capital Management, LLC 0.23% of their portfolio AUSTIN, TX 1,968,2162.0m $4.9m $4.9m 0.23% New
5 Cormorant Asset Management, LP 0.13% of their portfolio BOSTON, MA 1,000,0001.0m $2.5m $2.5m 0.13% New
6 VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio MALVERN, PA 614,923614.9k $1.5m $1.5m 0.00% Added +17.7k +17,731
7 WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio Boston, MA 556,233556.2k $1.4m $1.4m 0.00% Unchanged
8 MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio NEW YORK, NY 478,639478.6k $1.2m $1.2m 0.00% Added +378.8k +378,764
9 RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio NEW YORK, NY 471,570471.6k $1.2m $1.2m 0.00% Added +72.6k +72,570
10 Alyeska Investment Group, L.P. 0.00% of their portfolio CHICAGO, IL 300,000300.0k $750.0k $750.0k 0.00% Unchanged
11 Affinity Asset Advisors, LLC 0.03% of their portfolio NEW YORK, NY 250,000250.0k $625.0k $625.0k 0.03% New
12 RBF Capital, LLC 0.02% of their portfolio RENO, NV 200,000200.0k $500.0k $500.0k 0.02% Unchanged
13 Ensign Peak Advisors, Inc 0.00% of their portfolio SALT LAKE CITY, UT 159,835159.8k $399.6k $399.6k 0.00% Reduced -27.7k -27,665
14 Stonepine Capital Management, LLC 0.29% of their portfolio Bend, OR 154,595154.6k $386.5k $386.5k 0.29% Reduced -443.1k -443,087
15 ACADIAN ASSET MANAGEMENT LLC 0.00% of their portfolio Boston, MA 146,757146.8k $365.0k $365.0k 0.00% Added +134.1k +134,147
16 CITADEL ADVISORS LLC 0.00% of their portfolio MIAMI, FL 145,049145.0k $362.6k $362.6k 0.00% Reduced -1.2m -1,197,082
17 BRIDGEWAY CAPITAL MANAGEMENT, LLC 0.01% of their portfolio HOUSTON, TX 128,000128.0k $320.0k $320.0k 0.01% Added +77.5k +77,500
18 GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio BOSTON, MA 116,736116.7k $291.8k $291.8k 0.00% Reduced -10.8k -10,840
19 HRT FINANCIAL LP 0.00% of their portfolio NEW YORK, NY 116,288116.3k $290.0k $290.0k 0.00% New
20 BlackRock, Inc. 0.00% of their portfolio New York, NY 88,49588.5k $221.2k $221.2k 0.00% Added +17.8k +17,820
21 PRELUDE CAPITAL MANAGEMENT, LLC 0.02% of their portfolio NEW YORK, NY 83,99884.0k $210.0k $210.0k 0.02% New
22 Rangeley Capital, LLC 0.17% of their portfolio NEW CANAAN, CT 74,00074.0k $185.0k $185.0k 0.17% New
23 GSA CAPITAL PARTNERS LLP 0.01% of their portfolio LONDON, X0 72,35372.4k $181.0k $181.0k 0.01% Reduced -24.5k -24,471
24 VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio MALVERN, PA 65,13665.1k $162.8k $162.8k 0.00% Unchanged
25 JANE STREET GROUP, LLC 0.00% of their portfolio NEW YORK, NY 64,32364.3k $160.8k $160.8k 0.00% New
26 SUPERSTRING CAPITAL MANAGEMENT LP 0.09% of their portfolio NEW YORK, NY 55,35655.4k $138.4k $138.4k 0.09% New
27 NORTHERN TRUST CORP 0.00% of their portfolio CHICAGO, IL 34,82434.8k $87.1k $87.1k 0.00% New
28 XTX Topco Ltd 0.00% of their portfolio LONDON, X0 33,36133.4k $83.4k $83.4k 0.00% Reduced -1.3k -1,310
29 Qube Research & Technologies Ltd 0.00% of their portfolio LONDON, X0 20,20720.2k $50.5k $50.5k 0.00% Added +2.7k +2,715
30 China Universal Asset Management Co., Ltd. 0.00% of their portfolio SHANGHAI, F4 16,90016.9k $42.2k $42.2k 0.00% New
31 STATE STREET CORP 0.00% of their portfolio BOSTON, MA 15,96216.0k $39.9k $39.9k 0.00% Unchanged
32 MORGAN STANLEY 0.00% of their portfolio NEW YORK, NY 13,00013.0k $32.5k $32.5k 0.00% Unchanged
33 Caitong International Asset Management Co., Ltd 0.00% of their portfolio HONG KONG, K3 10,44310.4k $26.1k $26.1k 0.00% Added +10.4k +10,440
34 Pure Financial Advisors, LLC 0.00% of their portfolio SAN DIEGO, CA 10,10010.1k $25.2k $25.2k 0.00% Unchanged
35 Tower Research Capital LLC (TRC) 0.00% of their portfolio NEW YORK, NY 348348 $870 $870 0.00% Reduced -2.0k -2,023
36 JPMORGAN CHASE & CO 0.00% of their portfolio NEW YORK, NY 179179 $439 $439 0.00% Added +10 +10
37 BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio PARIS, I0 176176 $440 $440 0.00% Reduced -2 -2
38 Financial Management Professionals, Inc. 0.00% of their portfolio AUSTIN, TX 22 $5 $5 0.00% New
39 UBS Group AG 0.00% of their portfolio ZURICH, V8 22 $5 $5 0.00% Unchanged
40 SBI Securities Co., Ltd. 0.00% of their portfolio TOKYO, M0 22 $5 $5 0.00% Added +1 +1