Aptose Biosciences Inc.
Aptose Biosciences Inc. (APTO) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · APTO · as of Sep 30, 2025
Ownership Breakdown
3
Institutional Holders
▼ 1 vs Q2
$28,077
Total Inst. Value
▲ $7,354 vs Q2
2.55M
Shares Outstanding
freeFloat 19.58%
23,969
13F Shares Held
▼ 22 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
APTO largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 4 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
DRW SECURITIES, LLC biological products, (no diagnostic substances) | 19.8K | 77.42% | 77.42% | $23.12M | Nov 14, 2025 | — held |
GLEASON GROUP, INC. biological products, (no diagnostic substances) | 4.2K | 16.48% | 16.48% | $4.96M | Oct 16, 2025 | — held |
CALDWELL SUTTER CAPITAL, INC. biological products, (no diagnostic substances) | 2 | 0.01% | 0.01% | $2,000 | Oct 29, 2025 | — held |
TD WATERHOUSE CANADA INC. biological products, (no diagnostic substances) | 0 | 0.00% | 0.00% | $0 | Nov 3, 2025 | EXIT |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
0
Increased
+0 shares0
New Positions
first time holders0
Decreased
−0 shares1
Sold Out
fully exitedNet shares change (top 50)
+0
+0 / −0
Net new holders
-1
0 new / 1 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
APTO insider trading · insider activity
Source: SEC Form 4
Insiders have been net buyers of shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
0
Buy transactions
1
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Rice William G. Chair, President & CEO | Nov 25, 2024 | Purchase | 100,000 | $0.20 | $20.0K | 613.3K | Form 4 ↗ |
Rice William G. Chair, President & CEO | Nov 25, 2024 | Purchase | 50,000 | $0.25 | $12.5K | 50.0K | Form 4 ↗ |
Payne Fletcher Sr VP and CFO | Feb 5, 2024 | Award | 55,000 | $2.00 | $110.0K | 55.0K | Form 4 ↗ |
Bejar Rafael Sr VP & Chief Medical Officer | Feb 5, 2024 | Award | 35,000 | $2.00 | $70.0K | 35.0K | Form 4 ↗ |
LEDRU PHILIPPE Sr VP & Ch Commerical Officer | Feb 5, 2024 | Award | 11,000 | $2.00 | $22.0K | 11.0K | Form 4 ↗ |
Rice William G. Chair, President & CEO | Feb 5, 2024 | Award | 70,000 | $2.00 | $140.0K | 70.0K | Form 4 ↗ |
Seizinger Bernd R. director | Feb 5, 2024 | Award | 3,333 | $2.00 | $6.7K | 3.3K | Form 4 ↗ |
PLATZER ERICH director | Feb 5, 2024 | Award | 3,333 | $2.00 | $6.7K | 3.3K | Form 4 ↗ |
Vincent Mark D. director | Feb 5, 2024 | Award | 3,333 | $1.97 | $6.6K | 3.3K | Form 4 ↗ |
Ashe Carol Gail director | Feb 5, 2024 | Award | 3,333 | $2.00 | $6.7K | 3.3K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Aptose Biosciences Inc. (APTO) is primarily owned by institutional investors, who hold approximately 0.9% of total shares outstanding. Company insiders own approximately 80.42%, while retail and public investors account for the remaining 18.64%.
The largest institutional shareholder of Aptose Biosciences Inc. is DRW SECURITIES, LLC, holding approximately 19,761 shares — equal to 77.42% of outstanding shares — as of September 30, 2025.
A total of 3 institutional investors currently hold APTO stock, with a combined institutional value of approximately $28,077 as of the most recent 13F filing period.
Frequently asked questions
APTO ownershipAptose Biosciences Inc. (APTO) is primarily owned by institutional investors, who hold approximately 0.9% of shares. The largest shareholder is DRW SECURITIES, LLC with a 77.42% stake. Company insiders hold 80.42%. Data sourced from SEC Form 13F as of September 30, 2025.