Comparable stake leader
Philotimo Fund, LP
SEC ownership of DATA I/O CORP
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0000351998.
Disclosed value leader
Kanen Wealth Management LLC
Comparable rows
36/43
Latest evidence
31 Mar 2026
- Public ticker
- DAIO on Nasdaq
- Parsed ownership sources
- 13D/G, 13F, and 3/4/5
- Largest SEC-reported holder
- Philotimo Fund, LP
- Latest 13D/G holder
- Philotimo Fund, LP
- Latest parsed ownership date
- 31 Mar 2026
- Issuer CIK
- 0000351998
- Issuer location
- Redmond, WA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of DATA I/O CORP (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
Philotimo Fund, LP
Disclosed value leader
Kanen Wealth Management LLC
Comparable rows
36/43
Latest evidence
31 Mar 2026
13D/G
13F
3/4/5
Lead comparable stake: 9.1%
7 rows are not safely comparable across share classes.
13D/G row: Philotimo Fund, LP
Showing 1-8 of 43 holder rows.
Quick read
Philotimo Fund, LP leads the comparable SEC ownership view at 9.1%.
36 of 43 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens Philotimo Fund, LP's linked filing trail.
Comparable ownership
Top 5
Philotimo Fund, LP
9.1%
RENAISSANCE TECHNOLOGIES LLC
4.7%
Douglas Wells Brown
1.1%
Charles Joesph DiBona
1.1%
Sally A. Washlow
0.77%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 43 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Philotimo Fund, LP |
13D/G
Kanen David
|
9.1%
|
$1,939,063
839,421 shares
|
$0 | 22 May 2025 |
| RENAISSANCE TECHNOLOGIES LLC |
13D/G
13F
Company
|
4.7%
|
$1,321,664
437,637 shares
|
$0 | 31 Dec 2025 |
| Douglas Wells Brown |
3/4/5
Director
|
1.1%
|
$252,362
101,759 shares
|
— | 15 May 2025 |
| Charles Joesph DiBona |
3/4/5
Vice President & CFO
|
1.1%
|
$315,430
100,000 shares
|
— | 01 Sep 2025 |
| Sally A. Washlow |
3/4/5
Director
|
0.77%
|
$180,174
72,651 shares
|
— | 15 May 2025 |
| Edward J. Smith |
3/4/5
Director
|
0.67%
|
$156,525
63,115 shares
|
— | 15 May 2025 |
| Wentworth William O |
3/4/5
President, Director
|
0.56%
|
$147,195
52,872 shares
|
— | 03 Dec 2025 |
| Garrett Riley Larson |
3/4/5
Director
|
0.33%
|
$75,818
30,572 shares
|
— | 15 May 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 06 Jun 2025.
Buys
$0
Insiders: 0
Sells
$0
Insiders: 0
Net
$0
Shares: 0
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 0
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-14 of 14 reporting-owner rows connected to DATA I/O CORP. Open a relationship link for the CIK-to-CIK filing trail.
Rows
14
Largest Forms 3/4/5 holder
Anthony Ambrose
Net 12M change
$0
Latest report
03 Dec 2025
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Anthony Ambrose | President, Director | $1,351,908 | Mixed | 01 Jun 2024 | ||
| Joel S. Hatlen | Vice President CFO COO | $774,818 | Mixed | 01 Jun 2023 | ||
| Rajeev Gulati | Vice President CTO | $481,864 | Mixed | 01 Jun 2024 | ||
| Michael R. Tidwell | VP Mktg & Corp Bus Dev | $424,111 | Mixed | 01 Jun 2024 | ||
| Charles Joesph DiBona | Vice President & CFO | $315,430 | Mixed | 01 Sep 2025 | ||
| Mark J. Gallenberger | Director | $302,364 | Mixed | 20 May 2021 | ||
| Douglas Wells Brown | Director | $252,362 | Mixed | 15 May 2025 | ||
| Gerald Yat Ng | Vice President CFO | $246,053 | Mixed | 03 Jul 2024 | ||
| Sally A. Washlow | Director | $180,174 | Mixed | 15 May 2025 | ||
| Edward J. Smith | Director | $156,525 | Mixed | 15 May 2025 | ||
| Wentworth William O | President, Director | $147,195 | Mixed | 03 Dec 2025 | ||
| Garrett Riley Larson | Director | $75,818 | Mixed | 15 May 2025 | ||
| Cheemin Bo-Linn | Director | $66,994 | Mixed | 19 May 2022 | ||
| Steven M. Waszak | Director | $22,192 | Mixed | 03 Dec 2025 |
Recent insider transactions for DATA I/O CORP
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Wentworth William O | DAIO | Common Stock | Award | 2.08% | 1,100 | 53,972 | 03 Dec 2025 | Direct | ||
| Steven M. Waszak | DAIO | Common Stock | Award | 7,950 | 7,950 | 03 Dec 2025 | Direct | |||
| Wentworth William O | DAIO | Common Stock | Award | 16.4% | 7,455 | 52,872 | 02 Dec 2025 | Direct | ||
| Charles Joesph DiBona | DAIO | Common Stock | Award | 100,000 | 100,000 | 01 Sep 2025 | Direct |
* marks a reported price that did not pass the local price check.