ARCH Venture Partners XII, L.P.

CIK 1979765 · last filed 2024-02-20

ARCH Venture Partners XII, L.P. is a corporate insider who has filed 3 SEC Form 4 insider transactions across 2 companies since 2023. The most recent filing shows the insider bought $20.0M of PRME on Feb 20, 2024. Across all open-market trades the lifetime net is +$22.0M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $28.4M across reported positions. The firm reports its address in Chicago, IL. 19 SEC filings were submitted jointly with ARCH Venture Fund XII, L.P.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

Disclosed Exposure

$28.36M

Companies

Total Filings

Lifetime Open-Market Net

$21.96M

Charts

Trading activity, where the exposure sits, and each trade against the stock price.

PRME price and trades

Daily close with each Form 4 filing on this company marked: green = open-market buy, red = open-market sale, purple = grants, exercises, gifts and other non-market transactions. Marker size scales with the dollar value.

Shares held

Shares owned after each reported transaction on this company (direct holdings as reported).

Open-market buying and selling

by month

Dollar value of open-market purchases (code P, up) and sales (code S, down) across all companies, by filing month. Grants, exercises and gifts are excluded.

Exposure by company

latest

OfficerDirector10% owner* stale (no filing in 3 yrs)

Most recently reported shares × current price. Faded bars (*) have had no filing in 3 years, so the person may no longer hold them. Click a bar to chart that company.

Filer Profile

Reported Address

8755 W HIGGINS ROAD
SUITE 1025
CHICAGO, IL 60631

Phone

(773) 380-6600

State of Incorporation

Related Filers

ARCH Venture Fund XII, L.P. — 19 joint filings, latest 2026-05-04

ARCH Venture Partners XII, LLC — 19 joint filings, latest 2026-05-04

Keith Crandell — 17 joint filings, latest 2026-05-04

Steven Gillis — 17 joint filings, latest 2026-05-04

Robert Nelsen — 17 joint filings, latest 2026-05-04

Clinton Bybee — 4 joint filings, latest 2025-10-29

Kristina Burow — 4 joint filings, latest 2026-05-04

ARCH Venture Fund XIII, L.P. — 3 joint filings, latest 2025-11-14

Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.

Symbol	Role	Shares	Price	Disclosed Exposure	Lifetime OM Net	Filings	Latest Filed
PRME	10%+ Owner	6,128,297	$4.30	$26.35M	$20.00M	1	2024-02-20
NMRA	10%+ Owner	4,131,207	$0.49	$2.01M	$1.96M	2	2023-11-15

Recent Filings

3 filings

Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.

Filed	Symbol	Action	Net Shares	Net $	Link
2024-02-20	PRME	Buy (P)	+3,200,000	$20.00M	EDGAR
2023-11-15	NMRA	Buy (P)	+35,010	$412.1K	EDGAR
2023-11-13	NMRA	Buy (P)	+140,605	$1.54M	EDGAR

Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.