Keith Crandell - 01 Jul 2026 Form 4 Insider Report for Boundless Bio, Inc. (BOLD)

Reporting relationship
10%+ Owner
Issuer ticker
BOLD
Reported as of
01 Jul 2026
Net transaction value
-$39,840
Source evidence Original filing metadata and source links for verification. 4 source fields
SEC form
4
Accepted by SEC
06 Jul 2026, 17:44:44 UTC
Prior SEC filing
12 Jun 2026
Source filing
View source filing
Reporting owner 1 detail
Reporting owner signature
/s/ Keith Crandell, By: Mark McDonnell, attorney in-fact

Key filing fact

Keith Crandell filed Form 4 for Boundless Bio, Inc. (BOLD) on 06 Jul 2026.

Key facts

  • This page summarizes Keith Crandell's Form 4 filing for Boundless Bio, Inc. (BOLD).
  • 3 reported transactions and 5 derivative rows are listed below.
  • Accepted by SEC: 06 Jul 2026, 17:44.

Change

  • Previous filing in this sequence was filed on 12 Jun 2026.
  • Current net transaction value: -$39,840.

Research use

  • This tells you what this filing adds before you inspect full transaction and derivative tables.
  • You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (5)

CIK 0001219039 Primary reporting owner

CRANDELL KEITH

Relationship
10%+ Owner
Address
8755 W. HIGGINS ROAD, SUITE 1025, CHICAGO
Signature
/s/ Keith Crandell, By: Mark McDonnell, attorney in-fact
Signature date
06 Jul 2026
CIK 0001219043

BYBEE CLINTON

Relationship
10%+ Owner
Address
8755 W. HIGGINS ROAD, SUITE 1025, CHICAGO
Signature
/s/ Clinton Bybee, By: Mark McDonnell, attorney in-fact
Signature date
06 Jul 2026
CIK 0001219042

NELSEN ROBERT

Relationship
10%+ Owner
Address
8755 W. HIGGINS ROAD, SUITE 1025, CHICAGO
Signature
/s/ Robert Nelsen, By: Mark McDonnell, attorney in-fact
Signature date
06 Jul 2026
CIK 0001229592

GILLIS STEVEN

Relationship
10%+ Owner
Address
8755 WEST HIGGINS ROAD, SUITE 1025, CHICAGO
Signature
/s/ Steven Gillis, By: Mark McDonnell, attorney in-fact
Signature date
06 Jul 2026
CIK 0001569248

Burow Kristina

Relationship
10%+ Owner
Address
8755 W. HIGGINS ROAD,SUITE 1025, CHICAGO
Signature
/s/ Kristina Burow, By: Mark McDonnell, attorney in-fact
Signature date
06 Jul 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

BOLD transaction

Common Stock

Options Exercise

Transaction value
Shares
+16,000
Change %
Price
$1.03*
Shares after
16,000
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Options Exercise

Transaction value
Shares
+16,000
Change %
Price
$1.03*
Shares after
16,000
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Options Exercise

Transaction value
Shares
+16,000
Change %
Price
$1.03*
Shares after
16,000
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Options Exercise

Transaction value
Shares
+16,000
Change %
Price
$1.03*
Shares after
16,000
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Options Exercise

Transaction value
Shares
+16,000
Change %
Price
$1.03*
Shares after
16,000
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Sale

Transaction value
$39,840
Shares
-16,000
Change %
-100%
Price
$2.49
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Sale

Transaction value
$39,840
Shares
-16,000
Change %
-100%
Price
$2.49
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Sale

Transaction value
$39,840
Shares
-16,000
Change %
-100%
Price
$2.49
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Sale

Transaction value
$39,840
Shares
-16,000
Change %
-100%
Price
$2.49
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD transaction

Common Stock

Sale

Transaction value
$39,840
Shares
-16,000
Change %
-100%
Price
$2.49
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Footnotes
F1
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
683,759
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F2, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
683,759
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F2, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
683,759
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F2, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
683,759
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F2, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
683,759
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F2, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
828,570
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F3, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
828,570
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F3, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
828,570
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F3, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
828,570
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F3, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
828,570
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F3, F4
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
1,181,766
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F5, F6
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
1,181,766
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F5, F6
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
1,181,766
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F5, F6
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
1,181,766
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F5, F6
BOLD holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
1,181,766
Date
01 Jul 2026
Ownership
See footnotes
Footnotes
F5, F6

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

BOLD transaction Derivative

Stock Option (right to buy)

Options Exercise

Transaction value
Shares
-16,000
Change %
-100%
Price
$0.000000*
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Underlying class
Common Stock
Underlying amount
16,000
Exercise price
$1.03
Footnotes
F1, F7
BOLD transaction Derivative

Stock Option (right to buy)

Options Exercise

Transaction value
Shares
-16,000
Change %
-100%
Price
$0.000000*
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Underlying class
Common Stock
Underlying amount
16,000
Exercise price
$1.03
Footnotes
F1, F7
BOLD transaction Derivative

Stock Option (right to buy)

Options Exercise

Transaction value
Shares
-16,000
Change %
-100%
Price
$0.000000*
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Underlying class
Common Stock
Underlying amount
16,000
Exercise price
$1.03
Footnotes
F1, F7
BOLD transaction Derivative

Stock Option (right to buy)

Options Exercise

Transaction value
Shares
-16,000
Change %
-100%
Price
$0.000000*
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Underlying class
Common Stock
Underlying amount
16,000
Exercise price
$1.03
Footnotes
F1, F7
BOLD transaction Derivative

Stock Option (right to buy)

Options Exercise

Transaction value
Shares
-16,000
Change %
-100%
Price
$0.000000*
Shares after
0
Date
01 Jul 2026
Ownership
See footnote
Underlying class
Common Stock
Underlying amount
16,000
Exercise price
$1.03
Footnotes
F1, F7
* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 7 footnotes

Footnote F1

Represents a cashless stock option exercise by Kristina Burow. The net proceeds of such exercise were remitted to ARCH Venture Fund IX, L.P. (ARCH IX), ARCH Venture Fund IX Overage, L.P. (ARCH IX Overage), and ARCH Venture Fund X, L.P. (AVF X Overage LP). The stock option was granted to Kristina Burow in connection with her service on the board of directors of the Issuer.

Footnote F2

Represents shares held directly by ARCH Venture Fund IX, L.P. (ARCH IX). ARCH Venture Partners IX, L.P. (AVP IX LP) is the sole general partner of ARCH IX.

Footnote F3

Represents shares held directly by ARCH Venture Fund IX Overage, L.P. (ARCH IX Overage). ARCH Venture Partners IX Overage, L.P. (AVP IX Overage LP) is the sole general partner of ARCH IX Overage.

Footnote F4

ARCH Venture Partners IX, LLC (AVP IX LLC) is the sole general partner of each of AVP IX LP and AVP IX Overage LP. Keith Crandell, Robert Nelsen and Clinton Bybee are managing directors of AVP IX LLC (the AVP IX MDs). AVP IX LP and AVP IX Overage LP may be deemed to beneficially own the shares held by ARCH IX and ARCH IX Overage, respectively, AVP IX LLC may be deemed to beneficially own the shares held by ARCH IX and ARCH IX Overage, and each of the AVP IX MDs may be deemed to share the power to direct the disposition and vote of the shares held by ARCH IX and ARCH IX Overage. AVP IX LP, AVP IX Overage LP, AVP IX LLC, and the AVP IX MDs each disclaim beneficial ownership except to to the extent of any pecuniary interest therein, if any.

Footnote F5

Represents shares held directly by ARCH Venture Fund X Overage, L.P. (ARCH X Overage). ARCH Venture Partners X Overage, L.P. (AVP X Overage LP) is the sole general partner of ARCH X Overage.

Footnote F6

ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of AVP X Overage LP. Keith Crandell, Kristina Burow, Robert Nelsen and Steven Gillis are members of the investment committee of AVP X LLC (the AVP X Committee Members). AVP X Overage LP may be deemed to beneficially own the shares held by ARCH X Overage, AVP X LLC may be deemed to beneficially own the shares held by ARCH X Overage, and each of the AVP X Committee Members may be deemed to share the power to direct the disposition and vote of the shares held by ARCH X Overage. AVP X Overage LP, AVP X LLC, and the AVP X Committee Members each disclaim beneficial ownership except to the extent of any pecuniary interest therein, if any.

Footnote F7

The stock option vested in substantially equal monthly installments over the 11 months following June 23, 2025. The final unvested portion vested on June 15, 2026, the date of the Issuer's 2026 annual meeting of stockholders.

SEC remarks

This Form 4 is one of two reports relating to the same transaction being filed jointly by ARCH IX, AVP IX LP, ARCH IX Overage, AVP IX Overage LP, AVP IX LLC, ARCH X Overage, AVP X Overage LP, AVP X LLC, Robert Nelsen, Keith Crandell, Kristina Burow, Steve Gillis and Clint Bybee.

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