// company-profile

Aptose Biosciences Inc. Insider Trading

APTOF

Every SEC Form 4 insider trading filing for Aptose Biosciences Inc. (APTOF) — open-market buys and sells by directors and officers, option exercises, and cluster activity, updated as each filing is reported to the SEC.

ExchangeOTCSectorBiological Products, (No Diagnostic Substances)Inc.A6Filings21Insiders10
// api This Aptose Biosciences Inc. insider-trading data is served live by the Form4API insider trading API. Get the same data via API.
curl "https://api.form4api.com/v1/transactions?ticker=APTOF" -H "X-Api-Key: YOUR_API_KEY"

// activity-summary

No insider transactions in the last 30 days.

// 90-day insight

Over the last 90 days, Aptose Biosciences Inc. insiders sold $1.1M across 50 transactions with no open-market purchases.

  • Most active insider: PLATZER ERICH with 11 transactions totaling $2K.
  • Largest single sale: $1.1M by Rice William G. on Jun 30, 2026.

Activity skews bearish — sales outpace buys.

Institutional Ownership

Top 13F-HR holders of Aptose Biosciences Inc. as of 2026-06-30

— stable
Total reported AUM
$6,683
QoQ change
Reporting period
2026-06-30
#1
Gleason Group, Inc.
CIK 1822632
$6,341
4K shares
#2
CALDWELL SUTTER CAPITAL, INC.
CIK 702007
$327
202 shares
#3
Farther Finance Advisors, LLC
CIK 1992825
$15
10 shares

Data source: quarterly 13F-HR filings — institutional holders report positions within 45 days of quarter end. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →

Insider Transactions

Sourced from SEC EDGAR Form 4 filings. Updated hourly.

DateInsiderCompanyTypeSharesPriceValue
Jun 30, 2026Seizinger Bernd R.APTOF
Disposition
50,000$0.00$0K
Jun 30, 2026Vincent Mark D.APTOF
Disposition
50,000$0.00$0K
Jun 30, 2026Whitehead WarrenAPTOF
Disposition
33$1.72$0K
Jun 30, 2026Whitehead WarrenAPTOF
Disposition
3,333$0.00$0K
Jun 30, 2026Whitehead WarrenAPTOF
Disposition
100,000$0.00$0K

45 more transactions hidden

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