ARCH Venture Fund X, L.P.

CIK 1757011 · last filed 2025-10-29

ARCH Venture Fund X, L.P. is a corporate insider who has filed 3 SEC Form 4 insider transactions across 3 companies since 2021. The most recent filing shows the insider bought $50.0M of NMRA on Oct 29, 2025. Across all open-market trades the lifetime net is +$158.8M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $70.0M across reported positions.

"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

$69.98M

Companies

3

Total Filings

3

Lifetime Open-Market Net

$158.80M

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
NMRA	10%+ Owner	6,046,907	$1.63	$9.86M	$50.00M	1	2025-10-29
PRME	10%+ Owner	6,128,297	$3.08	$18.88M	$108.80M	1	2022-10-26
SANA	10%+ Owner	11,718,750	$3.52	$41.25M	$0	1	2021-02-10

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
2025-10-29	NMRA	Buy (P)	+19,157,000	$50.00M	EDGAR
2022-10-26	PRME	Mixed	+98,052,752	$108.80M	EDGAR
2021-02-10	SANA	Conv (C)	+218,750,000	$0	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.