Atlas Venture Associates IX, LLC

CIK 1671207 · last filed 2020-12-21

Atlas Venture Associates IX, LLC is a corporate insider who has filed 6 SEC Form 4 insider transactions across 3 companies since 2016. The most recent filing shows the insider sold $92.3M of SURF on Dec 21, 2020. Across all open-market trades the lifetime net is −$85.0M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $41.4M 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

$41.40M

Companies

3

Total Filings

6

Lifetime Open-Market Net

-$85.01M

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
Surface Oncology, Inc. (SURF) Delisted	10%+ Owner	2,945,453	$1.07	$3.15M	-$87.81M	2	2020-12-21
Cogent Biosciences, Inc. (UMRX) Delisted	10%+ Owner	3,267,483	—	—	$3.39M	1	2018-04-03
NTLA	10%+ Owner	3,729,788	$11.10	$41.40M	-$587.7K	3	2017-03-13

Recent Filings

6 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
2020-12-21	Surface Oncology, Inc. (SURF) Delisted	Sell (S)	−5,100,000	-$92.31M	EDGAR
2018-04-23	Surface Oncology, Inc. (SURF) Delisted	Mixed	+9,845,451	$4.50M	EDGAR
2018-04-03	Cogent Biosciences, Inc. (UMRX) Delisted	Mixed	+10,084,605	$3.39M	EDGAR
2017-03-13	NTLA	Sell (S)	−42,264	-$587.7K	EDGAR
2017-03-07	NTLA	Other (J)	−2,100,000	$0	EDGAR
2016-05-11	NTLA	Conv (C)	+13,289,364	$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.