Cardio Diagnostics Holdings, Inc. (CDIO) Ownership
CDIO ownership summary
as of October 17, 2026- Institutions
- 6.5% of shares outstanding
- Insiders
- 8.31% of shares outstanding
- Shares outstanding
- 3.0M
- Float
- 2.8M shares available to trade
- Short interest
- 0.03% 1,012 shares short
- Days to cover
- 0.03 short interest down 80.8% vs prior month
- Institutions 6.52%
- Insiders 8.31%
- Other investors 85.17%
CDIO top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Renaissance Technologies Corp | 1.66% | 49K | $83,148 | +33,852 (+220.6%) | June 30, 2026 |
| 2 | BlackRock Inc | 1.17% | 35K | $58,657 | — | June 30, 2026 |
| 3 | Geode Capital Management, LLC | 0.89% | 26K | $44,334 | −5,944 (−18.5%) | June 30, 2026 |
| 4 | Vanguard Capital Management, LLC | 0.68% | 20K | $34,062 | — | June 30, 2026 |
| 5 | Citadel Advisors Llc | 0.64% | 19K | $32,230 | +19,071 (0.0%) | June 30, 2026 |
| 6 | XTX Topco Ltd | 0.54% | 16K | $27,197 | +16,093 (0.0%) | June 30, 2026 |
| 7 | Jane Street Group LLC | 0.40% | 12K | $20,167 | −69,350 (−85.3%) | June 30, 2026 |
| 8 | State Street Corp | 0.34% | 10K | $17,067 | +10,099 (0.0%) | June 30, 2026 |
| 9 | Vanguard Fiduciary Trust Co | 0.10% | 2,824 | $4,773 | −1,145 (−28.8%) | June 30, 2026 |
| 10 | Tower Research Capital LLC | 0.06% | 1,809 | $3,057 | −383 (−17.5%) | June 30, 2026 |
| 11 | UBS Group AG | 0.02% | 656 | $1,109 | −9,263 (−93.4%) | June 30, 2026 |
| 12 | Wolverine Asset Management LLC | <0.01% | 104 | $176 | — | June 30, 2026 |
| 13 | Morgan Stanley - Brokerage Accounts | <0.01% | 100 | $169 | — | June 30, 2026 |
| 14 | SHP Wealth Management | <0.01% | 16 | $27 | — | June 30, 2026 |
| 15 | Advisor Group Holdings, Inc. | <0.01% | 16 | $27 | — | June 30, 2026 |
| 16 | SBI Securities Co Ltd | <0.01% | 10 | $17 | — | June 30, 2026 |
| 17 | Wells Fargo & Co | <0.01% | 2 | $3 | +2 (0.0%) | June 30, 2026 |
| 18 | DRW Securities, LLC | 0.00% | — | — | −40,463 (−100.0%) | March 31, 2026 |
| 19 | SRS Capital Advisors Inc | 0.00% | — | — | −6 (−100.0%) | March 31, 2026 |
| 20 | Citigroup Inc | 0.00% | — | — | −1 (−100.0%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 5 holders added 79K shares and 8 cut 127K.
CDIO top mutual fund and ETF holders
3 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Fidelity Extended Market Index | 0.53% | 16K | $26,464 | −84 (−0.5%) | August 31, 2026 |
| 2 | Fidelity Series Total Market Index | 0.10% | 2,826 | $4,776 | — | August 31, 2026 |
| 3 | Fidelity Total Market Index | 0.08% | 2,251 | $3,804 | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
CDIO insider transactions
latest 6| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2024-09-06 | Meeshanthini Dogan | Buy | $8.70 | 2,298 | $19,993 |
| 2024-09-06 | Robert Philibert | Buy | $8.70 | 1,135 | $9,874 |
| 2023-08-31 | Meeshanthini Dogan | Buy | $16.50 | 549 | $9,058 |
| 2023-08-28 | Robert Philibert | Buy | $18.00 | 600 | $10,800 |
| 2023-08-25 | Meeshanthini Dogan | Buy | $16.80 | 59 | $991 |
| 2023-08-24 | Robert Philibert | Buy | $18.00 | 533 | $9,594 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
CDIO shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns CDIO
Institutional investors own 6.5% of Cardio Diagnostics's shares and insiders 8.31%. The largest holder is Renaissance Technologies Corp with 1.66% of the shares (49K), as of June 30, 2026. Among the top 20 institutions, 5 added shares and 8 reduced their stake in the latest filings. Short interest is 0.03% of the float, or 0.03 days of average trading volume. The share count fell 77.5% since 2021.
Related: CDIO analyst forecast, CDIO key metrics. See the CDIO stock overview for the latest quote and news.
CDIO ownership FAQ
Who owns the most Cardio Diagnostics stock?
The largest shareholders of Cardio Diagnostics are Renaissance Technologies Corp (1.66%), BlackRock Inc (1.17%), Geode Capital Management, LLC (0.89%), Vanguard Capital Management, LLC (0.68%), Citadel Advisors Llc (0.64%).
What percentage of Cardio Diagnostics is owned by institutions?
Institutions hold 6.5% of Cardio Diagnostics's shares outstanding; insiders hold 8.31%.
Which funds own Cardio Diagnostics?
The largest fund holders of Cardio Diagnostics are Fidelity Extended Market Index (0.53%), Fidelity Series Total Market Index (0.10%), Fidelity Total Market Index (0.08%).
What is Cardio Diagnostics's short interest?
1,012 shares of Cardio Diagnostics were sold short, 0.03% of the float; at the average daily volume it would take 0.03 days to cover.
Are insiders buying or selling Cardio Diagnostics?
Of the latest 6 reported insider transactions in Cardio Diagnostics (since August 24, 2023), 6 were purchases and 0 were sales.
How many shares of Cardio Diagnostics are outstanding?
Cardio Diagnostics has 3.0M shares outstanding, of which 2.8M are in the public float.