Cytosorbents Corp
CTSO- Exchange
- Nasdaq
- Industry
- Surgical & Medical Instruments & Apparatus
- SEC CIK
- 0001175151
In the last 90 days, Cytosorbents Corp insiders filed 4 open-market purchases and 0 sales; 50 institutions reported holding it in 13F filings for Q2 2026, worth $6.04M in total; no superinvestor holds it.
Holders of 5% or more of CTSO
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Cytosorbents Corp, largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Avenir Corp | 13G/A | 8.30%5.23M shares | +2.60 ppfrom 5.70% | Dec 13, 20219 filings | Feb 13, 2026 | SEC |
| Satterfield Thomas A Jr | 13G | 6.56%4.00M shares | New | Jan 17, 20251 filing | Jan 17, 2025 | SEC |
| Avenue Venture Opportunities Fund, L.P. | 13G | 5.70%3.76M shares | New | May 28, 20251 filing | May 28, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
25 Schedule 13D and 13G filings on Cytosorbents Corp, newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Feb 13, 20265:56 PM ET | Avenir Corpand 1 other | 13G/A | 8.30%5.23M shares | +2.60 ppfrom 5.70% | Dec 31, 2025 | SEC |
| May 28, 20256:47 PM ET | Avenue Venture Opportunities Fund, L.P.and 7 others | 13G | 5.70%3.76M shares | New | Jun 26, 2024 | SEC |
| Apr 30, 202510:59 AM ET | Vanguard Group Inc | 13G/A | 3.11%1.95M shares | −4.02 ppfrom 7.13%Below 5% | Mar 31, 2025 | SEC |
| Apr 17, 20252:22 PM ET | Skylands Capital, LLC | 13G | 4.80%3.00M shares | −0.30 ppfrom 5.10%Below 5% | Mar 31, 2025 | SEC |
| Feb 14, 202510:22 AM ET | Avenir Corpand 1 other | 13G/A | 5.70%3.09M shares | – | Dec 31, 2024 | SEC |
| Jan 31, 20256:49 PM ET | Vanguard Group Inc | 13G | 7.13%3.90M shares | – | Dec 31, 2024 | SEC |
| Jan 17, 20254:05 PM ET | Satterfield Thomas A Jr | 13G | 6.56%4.00M shares | New | Jan 13, 2025 | SEC |
| Jan 7, 20251:26 PM ET | Skylands Capital, LLC | 13G | 5.10%2.78M shares | – | Dec 31, 2024 | SEC |
| Nov 14, 2024 | Granahan Investment Management Inc | 13G/AOld format | – | – | – | SEC |
| Feb 14, 2024 | Granahan Investment Management Inc | 13GOld format | – | New | – | SEC |
| Feb 14, 2024 | Avenir Corp | 13GOld format | – | – | – | SEC |
| Jan 8, 2024 | Skylands Capital, LLC | 13GOld format | – | – | – | SEC |
| Feb 14, 2023 | Avenir Corp | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2023 | Vanguard Group Inc | 13G/AOld format | – | – | – | SEC |
| Feb 7, 2023 | Skylands Capital, LLC | 13GOld format | – | New | – | SEC |
| Aug 11, 2022 | Avenir Corp | 13GOld format | – | – | – | SEC |
| Jul 8, 20224:57 PM ET | BlackRock Inc. | 13GOld format | – | – | – | SEC |
| Jun 28, 2022 | Avenir Corp | 13G/AOld format | – | – | – | SEC |
| Apr 25, 2022 | Avenir Corp | 13GOld format | – | – | – | SEC |
| Feb 9, 2022 | Vanguard Group Inc | 13G/AOld format | – | – | – | SEC |
| Feb 2, 20227:11 PM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Jan 7, 2022 | Avenir Corp | 13G/AOld format | – | – | – | SEC |
| Dec 13, 2021 | Avenir Corp | 13GOld format | – | New | – | SEC |
| Feb 10, 2021 | Vanguard Group Inc | 13GOld format | – | New | – | SEC |
| Jan 29, 20219:56 AM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
Form 144: proposed insider sales
1 notice from officers, directors and other affiliates planning to sell Cytosorbents Corp shares, newest first.
| Filed (ET) | Seller | Shares to sell | Market value | Planned sale | Broker | Filing |
|---|---|---|---|---|---|---|
| Aug 19, 20253:47 PM ET | Mariani Peter JOfficer | 10.5K | $11.4K | Aug 19, 2025 | Fidelity Brokerage Services LLC | SEC |