ARCH Venture Fund IX, L.P. 4
4 · Boundless Bio, Inc. · Filed Jul 6, 2026
Research Summary
AI-generated summary of this filing
Boundless Bio (BOLD) ARCH Venture Fund IX Exercises Options & Sells 16,000
What Happened
- ARCH Venture Fund IX (a 10% institutional holder) reported a cashless exercise of stock options tied to director Kristina Burow and an immediate sale on July 1, 2026. The filing shows 16,000 shares were exercised at $1.03 each (total exercise value $16,480) and 16,000 shares were sold in an open market transaction at $2.49 each (total sale proceeds $39,840). A related derivative disposal at $0.00 reflects conversion/settlement of the option position. The gross difference between sale proceeds and exercise cost is about $23,360.
Key Details
- Transaction date: 2026-07-01
- Actions: M = option exercise (16,000 shares @ $1.03; $16,480); S = sale (16,000 shares @ $2.49; $39,840); derivative conversion reported at $0.00
- Who exercised: option belonged to director Kristina Burow; exercise was cashless and net proceeds were remitted to ARCH funds (see footnote F1)
- Vesting: option vested in monthly installments after June 23, 2025; final unvested portion vested on June 15, 2026 (F7)
- Ownership structure notes: shares held across ARCH IX, ARCH IX Overage, and ARCH X Overage with associated general partner/investment committee disclosures (F2–F6)
- Shares owned after transaction: not specified in the provided filing excerpt
- Filing timeliness: Form 4 filed 2026-07-06 for a 2026-07-01 transaction — appears later than the SEC’s standard 2-business-day Form 4 deadline
Context
- This was a cashless option exercise immediately followed by an open-market sale — a common way for option holders to cover exercise costs and taxes once options vest. The filing involves a 10% institutional investor (ARCH funds) and an option originally granted for board service to Kristina Burow, so the trades reflect fund-level/compensation monetization rather than direct operational trading by company management.
Insider Transaction Report
Form 4
ARCH Venture Fund IX, L.P.
10% Owner
Transactions
- Exercise/Conversion
Common Stock
[F1]2026-07-01$1.03/sh+16,000$16,480→ 16,000 total(indirect: See footnote) - Sale
Common Stock
[F1]2026-07-01$2.49/sh−16,000$39,840→ 0 total(indirect: See footnote) - Exercise/Conversion
Stock Option (right to buy)
[F7][F1]2026-07-01−16,000→ 0 total(indirect: See footnote)Exercise: $1.03Exp: 2035-06-22→ Common Stock (16,000 underlying)
Holdings
- 683,759(indirect: See footnotes)
Common Stock
[F2][F4] - 828,570(indirect: See footnotes)
Common Stock
[F3][F4] - 1,181,766(indirect: See footnotes)
Common Stock
[F5][F6]
Footnotes (7)
- [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.
- [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.
- [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.
- [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.
- [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.
- [F6]ARCH Venture Partners X, LLC (AVP X LLC) is the sole general partner of AVP X Overage LP. Keith Crandell, Robert Nelsen, Kristina Burow 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.
- [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.