ABOS

Acumen Pharmaceuticals Inc Cross-source read$3.16 0.63%
Health CareCUSIP 00509G209· EOD Sep 8, 2026

Among active 13F managers last quarter, 12 opened and 8 added, while 4 reduced; the largest holder to move was ADAR1 Capital Management, LLC (+142%). Over the last 180 days, 2 insiders sold and none bought, a net -$90K in open-market trades.

Tracked 13F holders
80
43 in Q2 2026 filings
13F value (tracked)
$124.0M
Smart-money readMixed
Net sellingNet buying
Funds · active managers, latest 13F
20 adding · 4 trimming
Insiders · Form 4 open-market, 180d
0 buying · 2 selling · -$90K
US House · STOCK Act, 180d
0 buying · 0 selling

The legs disagree, or only one of them leans.

Price & smart-money activity

$3.16 0.63%5Y -80.3%
$0.90$5.03$9.17$13.31$17.4520212022202320242025202613104101091011515812131116216122011519121216616111215816151412171212442574810
Hover for who · click for detailEnd-of-day closing prices52w $1.23 – $3.37

Who owns ABOS?

80 tracked 13F filers · ranked by shares held

80 tracked 13F filers disclose a position in ABOS as of the latest SEC 13F filings, a combined $124.0M in reported value. Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

#FundSharesPosition valueLast moveAs ofHistory
1Ra Capital Management, L.P.21.0M
$56.1M
Held
Q2 2026
2Sands Capital Alternatives, LLC3.7M
$9.9M
Held
Q2 2026
3BlackRock, Inc.2.5M
$6.6M
14×
Added · +2.3M sh
Q2 2026
4Alyeska Investment Group, L.P.2.5M
$6.6M
Held
Q2 2026
5Franklin Templeton Inc2.3M
$5.4M
Held
Q1 2026
6ADAR1 Capital Management, LLC2.2M
$5.1M
+142%
Added · +1.3M sh
Q1 2026
7Vanguard Capital Management LLC1.7M
$4.5M
+11%
Added · +166K sh
Q2 2026
8Knollwood Investment Advisory, LLC1.6M
$4.3M
Held
Q2 2026
9Geode Capital Management, LLC1.1M
$3.0M
+174%
Added · +726K sh
Q2 2026
10Ikarian Capital, LLC1.1M
$2.8M
Held
Q2 2026
11Hudson Bay Capital Management LP955K
$2.5M
−1.4%
Reduced · −14K sh
Q2 2026
12Pathstone Holdings, LLC859K
$2.3M
Held
Q2 2026
13Millennium Management LLC660K
$1.6M
+13%
Added · +76K sh
Q1 2026
14Susquehanna International Group, LLP601K
$1.4M
+61%
Added · +228K sh
Q1 2026
15State Street Corp601K
$1.6M
+296%
Added · +449K sh
Q2 2026
16Two Sigma Investments, LP531K
$1.3M
+271%
Added · +388K sh
Q1 2026
17Renaissance Technologies LLC474K
$1.1M
+12%
Added · +51K sh
Q1 2026
18Vanguard Portfolio Management LLC321K
$857K
New
+321K sh
Q2 2026
19Bank Of America Corp320K
$756K
+33%
Added · +80K sh
Q1 2026
20Vanguard Fiduciary Trust Co291K
$778K
+46%
Added · +92K sh
Q2 2026
21Boothbay Fund Management, LLC273K
$729K
Held
Q2 2026
22Goldman Sachs Group Inc207K
$488K
+75%
Added · +89K sh
Q1 2026
23Marshall Wace, LLP193K
$455K
+823%
Added · +172K sh
Q1 2026
24Bridgeway Capital Management, LLC176K
$470K
Held
Q2 2026
25Morgan Stanley145K
$341K
−13%
Reduced · −22K sh
Q1 2026

Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

Is ABOS being bought or sold by institutions?

Last quarter, 12 funds opened a new position in ABOS and 8 added to an existing one, while 4 reduced. Based on 13F filings from active, signal-eligible managers (passive index funds and other mechanical holders are excluded from this count).

Opened
12
funds took a first position
Added
8
added to an existing position
Reduced
4
reduced, still holding
Biggest moves · ranked by size of the change, positions above a floor

Funds that own ABOS also own

CompanyCo-held byTheir position there
Nvidia CorpNVDA35 funds$120.7B
Alphabet Inc-CL AGOOGL35 funds$60.6B
Meta Platforms Inc-Class AMETA35 funds$32.6B
Eli Lilly & CoLLY35 funds$27.2B
Cardinal Health IncCAH35 funds$1.6B
Microsoft CorpMSFT34 funds$64.9B
Amazon.com IncAMZN34 funds$55.4B
JPMorgan Chase & CoJPM34 funds$19.2B
Lam Research CorpLRCX34 funds$16.4B
Bank Of America CorpBAC34 funds$11.3B
Berkshire Hathaway Inc-CL BBRK/B34 funds$9.7B
Texas Instruments IncTXN34 funds$5.3B

Ranked by how many of ABOS's tracked holders also hold each name. The last column is those co-holders' combined reported position in that name, not in ABOS.

Insider activity (Form 4)

Full insider page →
Sells · 180d
$90K
2 insiders
Net · 180d
-$90K
4 open-market transactions
DateInsiderRoleActionSharesValue
Jun 17, 2026Porter DerrellDirectorSell (S)13K$30K
Jun 16, 2026Porter DerrellDirectorSell (S)13K$30K
Jun 15, 2026Porter DerrellDirectorSell (S)6K$15K
Jun 9, 2026Fountain Nathan BDirectorSell (S)6K$14K
Mar 6, 2026Meisner Derek MChief Legal Officer & Corp SecSell (S)2K$7K
Feb 27, 2026Meisner Derek MChief Legal Officer & Corp SecSell (S)9K$28K
Jan 28, 2026Meisner Derek MChief Legal Officer & Corp SecSell (S)3K$8K
Jan 26, 2026Meisner Derek MChief Legal Officer & Corp SecSell (S)15K$45K
Jan 23, 2026Meisner Derek MChief Legal Officer & Corp SecSell (S)6K$11K
Jan 22, 2026Barton RussellChief Operating OfficerSell (S)462$850
Jan 22, 2026OConnell Daniel JosephChief Executive Officer, DirectorSell (S)3K$5K
Jan 22, 2026Zuga MattCFO & Chief Business OfficerSell (S)2K$3K

Do institutions, insiders and Congress agree?

Mixed signals

Where institutional funds (13F), corporate insiders (Form 4) and US House members (STOCK Act) are buying or selling the same name in the same window. Green is buying, red is selling.

SEC EDGAR 13F + Form 4 + US House STOCK Act{ }get_ticker_confluence · API & MCP

Signals by source

Insiders and Congress: last 180 days. Funds: latest 13F, top 100 holders incl. passive

SourceBuyingSellingNet
13F funds
Top 100 holders by value, passive included; the hero counts active managers only
2112
Insiders
Form 4 open-market
02-$90K
US House
STOCK Act trades
00$0
Sector rotation
ABOS is in Health Care, which smart money is rotating OUT OF
$5.0B

Capital Rotation reports where institutional capital disclosed rotating, as of the latest public SEC 13F filings. It is data, not investment advice, a recommendation, or a prediction. Filings lag about 45 days and cover long US equity positions only. Past disclosed flows do not indicate future prices. Do your own research; consult a licensed advisor.

Institutional ownership over time

43 tracked filers in Q2 2026 filingsstill filing
03876Q3 2024Q1 2025Q3 2025Q1 2026Q2 2026
tracked filers holding their reported valueQ2 2026 filings so far: $104.5M
Each bar counts tracked filers with a position in that quarter's filings, so the newest bar excludes filers still on an earlier quarter. Arkolith's tracked universe has grown over this window; part of any long-run rise is coverage, not new buyers.

Recent filings

15 most recent

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Connected entities for ABOS

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Ask your agent what changed in ABOS

This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.

Copy-paste
curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://arkolith.com/api/v1/stocks/ABOS/capital-change-brief"
Ask your agent
Use Arkolith's capital_change_brief for ABOS.
Tell me what changed, whether insider activity
corroborates it, and cite the SEC evidence.

13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for ABOS. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes.