QUMSU

Quantumsphere Acquisition Co$10.33 0.00%
FinancialsUSCUSIP G7387B122· EOD Aug 26, 2026◍ Confluence graph
Tracked 13F Holders
6
-2 QoQ
13F Value (tracked)
$2.6M
Insider Net · 180d
$0
0↑ 0↓
Recent Filings
0
Smart-money sentimentMixed
BearishBullish
13F funds (latest Q)0 adding · 0 trimming
Insider net (180d)$0

Price & smart-money activity

$10.33 0.00%1Y +3.1%
$9.98$10.12$10.26$10.40$10.54Aug 2025OctJan 2026MarJunAug187
Hover for who · click for detailEnd-of-day closing prices52w $10.02 – $10.50

Who owns QUMSU?

6 tracked 13F filers

6 tracked 13F filers disclose a position in QUMSU as of the latest SEC 13F filings, a combined $2.6M 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.

#FundPosition valueSharesLast moveAs ofHistory
1Westchester Capital Management, LLC
$1.0M
100K
Held
Q1 2026
2GABELLI & Co INVESTMENT ADVISERS, INC.
$699K
68K
Held
Q2 2026
3GABELLI FUNDS LLC
$591K
57K
Held
Q1 2026
4Clear Street Group Inc.
$239K
23K
+3.0%
Added · +682 sh
Q2 2026
5JPMORGAN CHASE & CO
$102K
10K
Held
Q1 2026
6UBS Group AG
$5K
464
+1.1%
Added · +5 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.

Funds that own QUMSU also own

CompanyCo-held byCombined value
WARNER BROS DISCOVERY INCWBD3 funds$235.8M
ELECTRONIC ARTS INCEA3 funds$213.6M
NORFOLK SOUTHERN CORPNSC3 funds$176.5M
CHART INDUSTRIES INCGTLS3 funds$175.6M
WEBSTER FINANCIAL CORPWBS3 funds$154.6M
DIGITALBRIDGE GROUP INCDBRG3 funds$73.1M
UNIFIRST CORP/MAUNF3 funds$71.4M
PENUMBRA INCPEN3 funds$60.6M
JANUS HENDERSON GROUP PLCJHG3 funds$51.9M
KENVUE INCKVUE3 funds$35.6M
AGRICULTURE & NATURAL SOLUTIANSC3 funds$24.2M
GIGCAPITAL8 CORP-AGIW3 funds$18.8M

Ranked by how many of QUMSU's institutional holders also hold each name, a cross-fund conviction signal.

Insider activity (Form 4)

No open-market insider transactions on file yet. Grants, gifts, and exercises live on the full insider page.

Institutional ownership over time

5 funds-18 since Q3 2025
01223Q3 2025Q4 2025Q1 2026
funds holding aggregate valuelatest $1.9M

Share classes

Class13F holdersValue held
QUMSORD SHS24 funds$56.8M
QUMSRSPACS21 funds$1.2M
QUMSUthis pageUNIT 07/30/20306 funds$2.6M

Same issuer, multiple share classes. The consensus leaderboards count this company once across all classes; this is the per-class detail.

Recent filings

0 shown

No filings captured for this ticker in the live stream yet.

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Ask your agent what changed in QUMSU

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/QUMSU/capital-change-brief"
Ask your agent
Use Arkolith's capital_change_brief for QUMSU.
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 QUMSU. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes.