Boundless Bio, Inc. (BOLD)
Nasdaq: BOLD · Pharmaceutical Preparations · San Diego, CA · filing with the SEC since 2020
Who owns Boundless Bio, Inc.
As filed with the SECHolders of 5% or more
4
Fmr LLC holds 12% of COMMON STOCK, as its SCHEDULE 13G/A filed Feb 5, 2026 says.
Directors and officers
10
report now, of 14 people on the record since 2024. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 4 named at left.
Holders of 5% or moreshare of the class, as filed
Fmr LLC
SCHEDULE 13G/A · filed Feb 5, 2026 · COMMON STOCK
Tang Capital Management, LLC
SCHEDULE 13G · filed Jun 29, 2026 · Common stock, par value $0.0001 per share
Zachary Hornby
SCHEDULE 13G · filed Aug 27, 2026 · Common Stock, par value $0.0001 per share
ADAR1 Capital Management, LLC
SCHEDULE 13G · filed Aug 14, 2026 · Common Stock, par value $0.0001 per share
Citadel Securities Group LP
SCHEDULE 13G/A · filed Aug 14, 2026 · Common stock, par value $0.0001 per share (the "Shares") · reported falling below 5%, from 6.4% in Dec 4, 2025
Nextech VI GP S.a. r.l.
SCHEDULE 13G/A · filed Feb 17, 2026 · Common Stock, par value $0.0001 per share · reported falling below 5%
RA Capital Management, L.P.
SCHEDULE 13G/A · filed Aug 14, 2025 · Common Stock, par value $0.0001 per share · reported falling below 5%
What BOLD reports owning in othersstakes of 5% or more, and other ties
Boundless Bio, Inc. reports no stake in another company in the record.
Insider tradesForm 4
0sales
0purchases
0sales on a scheduled plan
0people selling
$0sold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Nov 10, 2025 to Nov 10, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
2024 runs to Nov 10, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window4 of 34 on the roster
| Person | Role as filed | Sales | Sold | On a plan | Buys | Bought |
|---|---|---|---|---|---|---|
| Tang Capital Management LLC | 10% owner | 1 | $100,000 | 0 | 0 | $0 |
| Tang Kevin | 10% owner | 0 | $0 | 0 | 35 | $2.0M |
| Arch Venture Partners Ix, L.P. | 10% owner | 1 | $0 | 0 | 0 | $0 |
| Gillis Steven | 10% owner | 1 | $0 | 0 | 0 | $0 |