Data I/O Corp (DAIO) shareholders
DAIONasdaqInstruments For Meas & Testing of Electricity & Elec SignalsFiscal year ends December 31
Financials through Q3 FY2026, quarter ended Sep 30, 2026Last filing: 10-Q on Nov 13, 2026Score 9/3036% below fair value
$2.56−0.08 (-3.03%)
Close on Nov 13, 2026Market cap $26.61MP/E –Yield –
Ownership
Institutional holdings as of Jun 30, 2026, from 13F filings
Held by institutions
29.9%
3M of 10M shares
Institutional holders
35
9 new, 3 sold out
Net institutional buying
0M
In Q2 2026
Insider trades, 12 months
2 buys · 0 sales
Net bought $1,000.00K
Shares held by institutions
Holders of more than 5%
Latest Schedule 13D (active) or 13G (passive) filed by each holder
| Holder | Shares | % of class | Filing | As of |
|---|---|---|---|---|
| David Sandberg Joint filing with Red Oak Partners, LLC (11.20%), The Red Oak Fund, LP (7.30%) | 1,492,536 | 11.20% | 13G (passive) | Oct 20, 2026 |
| Lytton Laurence W Joint filing with Lytton-Kambara Foundation (5.80%) | 1,026,424 | 9.90% | 13G (passive) | Jun 17, 2026 |
| Kanen David Joint filing with Kanen Wealth Management LLC (8.90%), Philotimo Fund, LP (5.30%) | 839,421 | 9.10% | 13G (passive) amendment | May 22, 2025 |
Top institutional holders
13F holdings as of Jun 30, 2026
| Holder | Shares | % of DAIO | Value | Change | % of portfolio |
|---|---|---|---|---|---|
| Kanen Wealth Management LLC | 839,421 | 8.07% | $3.29M | – | 0.80% |
| Renaissance Technologies LLC | 392,443 | 3.78% | $1.55M | −15,200 | 0.00% |
| Penbrook Management LLC | 355,850 | 3.42% | $1.40M | −1,000 | 0.89% |
| Vanguard Capital Management LLC | 323,672 | 3.11% | $1.28M | +24,275 | 0.00% |
| Kovack Advisors, Inc. | 285,481 | 2.75% | $1.11M | +17,500 | 0.05% |
| Dimensional Fund Advisors LP | 140,679 | 1.35% | $554.28K | – | 0.00% |
| Geode Capital Management, LLC | 115,057 | 1.11% | $453.42K | +28,190 | 0.00% |
| Acadian Asset Management LLC | 108,582 | 1.04% | $427.00K | −15,537 | 0.00% |
| Citadel Advisors LLC | 86,869 | 0.84% | $342.26K | New | 0.00% |
| Essex Investment Management Co LLC | 74,558 | 0.72% | $293.76K | −83 | 0.04% |
| Vanguard Fiduciary Trust Co | 58,643 | 0.56% | $231.05K | +12,790 | 0.00% |
| Susquehanna International Group, Llp | 48,548 | 0.47% | $191.28K | +21,711 | 0.00% |
| Steward Partners Investment Advisory, LLC | 43,472 | 0.42% | $171.28K | – | 0.00% |
| Thompson Davis & Co., Inc. | 23,533 | 0.23% | $92.72K | New | 0.06% |
| James Investment Research Inc | 22,402 | 0.22% | $88.26K | – | 0.01% |
| NewEdge Advisors, LLC | 22,402 | 0.22% | $88.26K | – | 0.00% |
| Northern Trust Corp | 21,827 | 0.21% | $86.00K | +8,351 | 0.00% |
| LPL Financial LLC | 21,000 | 0.20% | $82.74K | −1,545 | 0.00% |
| Jane Street Group, LLC | 17,727 | 0.17% | $69.84K | New | 0.00% |
| Legato Capital Management LLC | 17,550 | 0.17% | $69.15K | – | 0.01% |
Institutional buying and selling by quarter
Positions opened, added to, reduced and closed by 13F filers
| Quarter | Holders | Shares held | % of shares | New / added | Reduced / closed | Shares bought | Shares sold |
|---|---|---|---|---|---|---|---|
| Q2 2026 | 35 | 3M | 29.9% | 9 / 9 | 6 / 3 | 0M | 0M |
| Q1 2026 | 29 | 3M | 27.6% | 7 / 3 | 6 / 4 | 0M | 0M |
| Q4 2025 | 27 | 3M | 28.4% | 3 / 8 | 7 / 2 | 0M | 0M |
| Q3 2025 | 26 | 3M | 30.7% | 2 / 5 | 7 / 2 | 0M | 0M |
| Q2 2025 | 26 | 3M | 33.5% | 3 / 10 | 6 / 3 | 0M | 0M |
| Q1 2025 | 26 | 3M | 29.5% | 1 / 6 | 5 / 4 | 0M | 0M |
| Q4 2024 | 29 | 3M | 30.2% | 4 / 3 | 6 / 4 | 0M | 0M |
| Q3 2024 | 29 | 3M | 30.5% | 3 / 5 | 7 / 5 | 0M | 0M |
| Q2 2024 | 32 | 3M | 31.6% | 3 / 6 | 9 / 3 | 0M | 0M |
| Q1 2024 | 32 | 3M | 32.3% | 3 / 12 | 10 / 1 | 1M | 0M |
| Q4 2023 | 30 | 3M | 27.5% | 3 / 9 | 9 / 2 | 0M | 1M |
| Q3 2023 | 29 | 3M | 32.5% | 2 / 7 | 12 / 2 | 0M | 0M |
Top mutual fund and ETF holders
Latest monthly portfolio reports (Form N-PORT)
20 funds held DAIO in Q2 2026, 39% of their shares through ETFs. Each fund counts once per quarter, from its quarter-end report.
| Fund | Shares | % of DAIO | Value | % of fund | As of |
|---|---|---|---|---|---|
| Philotimo Focused Growth & Income | 327,401 | 3.15% | $1.29M | 0.94% | Jun 30, 2026 |
| Vanguard Total Stock Market Index Fund | 214,242 | 2.06% | $844.11K | 0.00% | Jun 30, 2026 |
| Vanguard Extended Market Index Fund | 90,237 | 0.87% | $355.53K | 0.00% | Jun 30, 2026 |
| U.S. Micro Cap Portfolio | 46,137 | 0.44% | $131.03K | 0.00% | Jul 31, 2026 |
| U.S. Small Cap Portfolio | 31,665 | 0.30% | $89.93K | 0.00% | Jul 31, 2026 |
| Fidelity Extended Market Index Fund | 25,475 | 0.25% | $107.76K | 0.00% | May 31, 2026 |
| Fidelity Total Market Index Fund | 19,731 | 0.19% | $83.46K | 0.00% | May 31, 2026 |
| Fidelity Nasdaq Composite Index Fund | 15,054 | 0.14% | $63.68K | 0.00% | May 31, 2026 |
| Fidelity Series Total Market Index Fund | 11,134 | 0.11% | $47.10K | 0.00% | May 31, 2026 |
| LVIP Dimensional U.S. Core Equity 2 Fund | 7,146 | 0.07% | $28.16K | 0.00% | Jun 30, 2026 |
| U.S. Sustainability Core 1 Portfolio | 4,622 | 0.04% | $13.13K | 0.00% | Jul 31, 2026 |
| U.S. Core Equity 2 Portfolio | 4,203 | 0.04% | $11.94K | 0.00% | Jul 31, 2026 |
| Dimensional US Core Equity 1 ETF | 3,526 | 0.03% | $10.01K | 0.00% | Jul 31, 2026 |
| Dimensional U.S. Equity Market ETF | 3,489 | 0.03% | $9.91K | 0.00% | Jul 31, 2026 |
| Dimensional US Sustainability Core 1 ETF | 3,442 | 0.03% | $9.78K | 0.00% | Jul 31, 2026 |
Officers, directors and major owners
People who filed Forms 3, 4 or 5 in the last two years
| Name | Role | Shares owned | % of shares | Latest filing |
|---|---|---|---|---|
| William O. Wentworth | President, Director | 52,872 | 0.51% | Dec 5, 2025 |
| Charles Joseph DiBona | Vice President & CFO | 89,655 | 0.86% | Sep 3, 2026 |
| Gerald Yat Ng | Vice President CFO | 88,191 | 0.85% | Feb 12, 2025 |
| Steven M. Waszak | Director | 24,210 | 0.23% | Jul 10, 2026 |
| Edward J. Smith | Director | 79,375 | 0.76% | Jul 10, 2026 |
| Garrett Riley Larson | Director | 46,832 | 0.45% | Jul 10, 2026 |
| Sally A. Washlow | Director | 88,911 | 0.86% | Jul 10, 2026 |
| Douglas Wells Brown | Director | 101,759 | 0.98% | May 19, 2025 |
| David Sandberg | 10% owner | – | – | Oct 27, 2026 |
| Red Oak Long Fund, LP | 10% owner | – | – | Oct 27, 2026 |
| Red Oak Partners, LLC | 10% owner | 373,133 | 3.59% | Oct 27, 2026 |
| Red Oak Fund, LP | 10% owner | – | – | Oct 27, 2026 |
Insider trades
Common stock transactions reported on Form 4, newest first
| Insider | Date | Transaction | Shares | Price | Value | Shares after |
|---|---|---|---|---|---|---|
| Red Oak Partners, LLC 10% owner | Oct 20, 2026 | Buy | +130,199 | $2.68 | $348.93K | 130,199 |
| Red Oak Partners, LLC 10% owner | Oct 20, 2026 | Buy | +242,934 | $2.68 | $651.06K | 242,934 |
| Charles Joseph DiBona Vice President & CFO | Sep 1, 2026 | Tax withholding | −10,345 | $2.89 | $29.90K | 89,655 |
| Garrett Riley Larson Director | Jul 8, 2026 | Award | +16,260 | $3.56 | $57.89K | 46,832 |
| Edward J. Smith Director | Jul 8, 2026 | Award | +16,260 | $3.56 | $57.89K | 79,375 |
| Steven M. Waszak Director | Jul 8, 2026 | Award | +16,260 | $3.56 | $57.89K | 24,210 |
| Sally A. Washlow Director | Jul 8, 2026 | Award | +16,260 | $3.56 | $57.89K | 88,911 |
| William O. Wentworth President, Director | Dec 3, 2025 | Award | +1,100 | $2.80 | $3.08K | 53,972 |
| Steven M. Waszak Director | Dec 3, 2025 | Award | +7,950 | $2.79 | $22.18K | 7,950 |
| William O. Wentworth President, Director | Dec 2, 2025 | Award | +7,455 | $2.78 | $20.72K | 52,872 |
| Charles Joseph DiBona Vice President & CFO | Sep 1, 2025 | Award | +100,000 | $3.15 | $315.00K | 100,000 |
| Garrett Riley Larson Director | May 15, 2025 | Award | +20,300 | $2.48 | $50.34K | 30,572 |
| Douglas Wells Brown Director | May 15, 2025 | Award | +20,300 | $2.48 | $50.34K | 101,759 |
| Sally A. Washlow Director | May 15, 2025 | Award | +20,300 | $2.48 | $50.34K | 72,651 |
| Edward J. Smith Director | May 15, 2025 | Award | +20,300 | $2.48 | $50.34K | 63,115 |
| Edward J. Smith Director | May 7, 2025 | Buy | +5,000 | $2.46 | $12.30K | 42,815 |
| William O. Wentworth President, Director | May 6, 2025 | Buy | +10,332 | $2.42 | $25.00K | 45,417 |
| William O. Wentworth President | May 2, 2025 | Award | +10,585 | $2.36 | $24.98K | 35,085 |
| William O. Wentworth President, Director | May 1, 2025 | Buy | +10,585 | $2.36 | $24.98K | 35,085 |
| Garrett Riley Larson Director | Jan 23, 2025 | Award | +5,272 | $2.91 | $15.34K | 5,272 |
| Douglas Wells Brown Director | Aug 26, 2024 | Buy | +3,000 | $2.66 | $7.98K | 81,459 |
| Gerald Yat Ng Vice President CFO | Jul 3, 2024 | Tax withholding | −5,559 | $2.79 | $15.51K | 88,191 |
| Gerald Yat Ng Vice President CFO | Jun 1, 2024 | Award | +18,750 | $2.87 | $53.81K | 93,750 |
| Anthony Ambrose President, Director | Jun 1, 2024 | Award | +37,500 | $2.87 | $107.63K | 471,048 |
| Anthony Ambrose President, Director | Jun 1, 2024 | Tax withholding | −8,870 | $2.87 | $25.46K | 433,548 |
| Anthony Ambrose President, Director | Jun 1, 2024 | Tax withholding | −9,978 | $2.87 | $28.64K | 442,418 |
| Anthony Ambrose President, Director | Jun 1, 2024 | Tax withholding | −6,652 | $2.87 | $19.09K | 452,396 |
| Michael R. Tidwell VP Mktg & Corp Bus Dev | Jun 1, 2024 | Tax withholding | −2,223 | $2.87 | $6.38K | 139,103 |
| Michael R. Tidwell VP Mktg & Corp Bus Dev | Jun 1, 2024 | Tax withholding | −1,976 | $2.87 | $5.67K | 135,274 |
| Michael R. Tidwell VP Mktg & Corp Bus Dev | Jun 1, 2024 | Award | +12,500 | $2.87 | $35.88K | 147,774 |
| Michael R. Tidwell VP Mktg & Corp Bus Dev | Jun 1, 2024 | Tax withholding | −1,853 | $2.87 | $5.32K | 137,250 |
| Rajeev Gulati Vice President CTO | Jun 1, 2024 | Award | +12,500 | $2.87 | $35.88K | 167,897 |
| Rajeev Gulati Vice President CTO | Jun 1, 2024 | Tax withholding | −1,976 | $2.87 | $5.67K | 155,397 |
| Rajeev Gulati Vice President CTO | Jun 1, 2024 | Tax withholding | −1,853 | $2.87 | $5.32K | 157,373 |
| Rajeev Gulati Vice President CTO | Jun 1, 2024 | Tax withholding | −1,482 | $2.87 | $4.25K | 159,226 |
| Rajeev Gulati Vice President CTO | May 18, 2024 | Tax withholding | −2,223 | $2.91 | $6.47K | 160,708 |
| Michael R. Tidwell Vice President Mktg & Bus Dev | May 18, 2024 | Tax withholding | −2,965 | $2.91 | $8.63K | 141,326 |
| Anthony Ambrose President, Director | May 18, 2024 | Tax withholding | −9,978 | $2.91 | $29.04K | 459,058 |
| William O. Wentworth Director | May 16, 2024 | Award | +14,100 | $2.93 | $41.31K | 24,500 |
| Sally A. Washlow Director | May 16, 2024 | Award | +14,100 | $2.93 | $41.31K | 52,351 |
| Edward J. Smith Director | May 16, 2024 | Award | +14,100 | $2.93 | $41.31K | 37,815 |
| Douglas Wells Brown Director | May 16, 2024 | Award | +14,100 | $2.93 | $41.31K | 78,459 |
| Anthony Ambrose President, Director | May 14, 2024 | Gift | −7,500 | $2.95 | $22.13K | 469,036 |
| Gerald Yat Ng Vice President Finance | Jul 3, 2023 | Award | +75,000 | $4.36 | $327.00K | 75,000 |
| Anthony Ambrose President, Director | Jun 1, 2023 | Tax withholding | −9,450 | $4.35 | $41.11K | 416,526 |
| Anthony Ambrose President, Director | Jun 1, 2023 | Tax withholding | −6,300 | $4.35 | $27.40K | 425,976 |
| Anthony Ambrose President, Director | Jun 1, 2023 | Award | +60,000 | $4.35 | $261.00K | 476,526 |
| Joel S. Hatlen Vice President CFO COO | Jun 1, 2023 | Tax withholding | −1,822 | $4.35 | $7.93K | 180,397 |
| Joel S. Hatlen Vice President CFO COO | Jun 1, 2023 | Tax withholding | −2,278 | $4.35 | $9.91K | 178,119 |
| Rajeev Gulati Vice President CTO | Jun 1, 2023 | Award | +20,000 | $4.35 | $87.00K | 162,931 |
| Rajeev Gulati Vice President CTO | Jun 1, 2023 | Tax withholding | −2,103 | $4.35 | $9.15K | 142,931 |
| Rajeev Gulati Vice President CTO | Jun 1, 2023 | Tax withholding | −1,572 | $4.35 | $6.84K | 145,034 |
| Michael R. Tidwell Vice President Mktg & Bus Dev | Jun 1, 2023 | Tax withholding | −1,758 | $4.35 | $7.65K | 125,757 |
| Michael R. Tidwell Vice President Mktg & Bus Dev | Jun 1, 2023 | Tax withholding | −1,465 | $4.35 | $6.37K | 124,291 |
| Michael R. Tidwell Vice President Mktg & Bus Dev | Jun 1, 2023 | Award | +20,000 | $4.35 | $87.00K | 144,291 |
| Anthony Ambrose President, Director | May 26, 2023 | Gift | −5,000 | $4.40 | $22.00K | 432,276 |
| Rajeev Gulati Vice President CTO | May 20, 2023 | Tax withholding | −1,882 | $4.54 | $8.54K | 146,606 |
| Joel S. Hatlen Vice President CFO COO | May 20, 2023 | Tax withholding | −2,132 | $4.54 | $9.68K | 182,219 |
| Anthony Ambrose President, Director | May 20, 2023 | Tax withholding | −6,300 | $4.54 | $28.60K | 437,276 |
| Douglas Wells Brown Director | May 18, 2023 | Award | +10,400 | $4.45 | $46.28K | 64,359 |
Awards, option exercises, tax withholding and gifts are shown alongside open-market buys and sales. Each name links to the filing on SEC EDGAR.
Short interest
Shares sold short and not yet bought back, as of Oct 30, 2026 (FINRA, reported twice a month)
Short % of float
0.14%
0M shares short
Days to cover
1.0
At 0M shares a day
Change since last report
+66.6%
From 0M shares
Short volume, 20 days
25.0%
Of volume reported to FINRA
Shares sold short, last 12 months
Short sale volume counts trades marked short on any given day, including market-maker hedging, so it runs far higher than the share of Data I/O's stock actually held short. Settlement fails (shares not delivered on time) peaked at 576 shares on Aug 20, 2026 over the last 90 days.
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