Cytosorbents Corporation
Cytosorbents Corporation (CTSO) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · CTSO · as of Sep 30, 2025
Ownership Breakdown
50
Institutional Holders
▲ 5 vs Q2
$15.42M
Total Inst. Value
▼ $5.33M vs Q2
62.79M
Shares Outstanding
freeFloat 87.74%
16.51M
13F Shares Held
▲ 68,487 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
CTSO largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
AVENIR CORP surgical & medical instruments & apparatus | 5.08M | 8.12% | 8.12% | $4.75B | Nov 14, 2025 | ▲ 24.3K |
VANGUARD GROUP INC surgical & medical instruments & apparatus | 2.20M | 3.52% | 3.52% | $2.06B | Nov 7, 2025 | ▲ 79.5K |
SKYLANDS CAPITAL, LLC surgical & medical instruments & apparatus | 2.13M | 3.40% | 3.40% | $1.99B | Nov 6, 2025 | ▼ 489.4K |
NEUBERGER BERMAN GROUP LLC surgical & medical instruments & apparatus | 1.60M | 2.55% | 2.55% | $1.49B | Nov 12, 2025 | ▲ 6.3K |
CM MANAGEMENT, LLC surgical & medical instruments & apparatus | 1.29M | 2.06% | 2.06% | $1.20B | Nov 13, 2025 | ▲ 38.1K |
BLACKROCK, INC. surgical & medical instruments & apparatus | 764.8K | 1.22% | 1.22% | $714.41M | Nov 12, 2025 | ▲ 19.2K |
SARGENT INVESTMENT GROUP, LLC surgical & medical instruments & apparatus | 738.7K | 1.18% | 1.18% | $690.02M | Nov 14, 2025 | ▼ 7.5K |
GEODE CAPITAL MANAGEMENT, LLC surgical & medical instruments & apparatus | 601.5K | 96.07% | 96.07% | $561.98M | Nov 12, 2025 | — held |
CIBC PRIVATE WEALTH GROUP, LLC surgical & medical instruments & apparatus | 172.6K | 27.58% | 27.58% | $161.27M | Nov 24, 2025 | — held |
surgical & medical instruments & apparatus | 172.6K | 27.58% | 27.58% | $161.27M | Nov 12, 2025 | NEW |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
16
Increased
+401.9K shares6
New Positions
first time holders10
Decreased
−546.4K shares0
Sold Out
fully exitedNet shares change (top 50)
144.5K
+401.9K / −546.4K
Net new holders
+12
6 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
CTSO insider trading · insider activity
Source: SEC Form 4
1
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Chan Phillip P. Chief Executive Officer | Nov 18, 2025 | Award | 100,000 | $0.64 | $64.0K | 1.48M | Form 4 ↗ |
Chan Phillip P. Chief Executive Officer | Aug 8, 2025 | Award | 105,600 | — | — | 1.38M | Form 4 ↗ |
Chan Phillip P. Chief Executive Officer | Aug 8, 2025 | Award | 136,400 | $1.00 | $136.4K | 136.4K | Form 4 ↗ |
Jones Edward Raymond director | Aug 8, 2025 | Award | 22,000 | $1.00 | $22.0K | 22.0K | Form 4 ↗ |
BATOR MICHAEL G. director | Aug 8, 2025 | Award | 44,000 | $1.00 | $44.0K | 44.0K | Form 4 ↗ |
MARIANI PETER J Chief Financial Officer | Aug 8, 2025 | Award | 71,500 | — | — | 538.1K | Form 4 ↗ |
MARIANI PETER J Chief Financial Officer | Aug 8, 2025 | Award | 90,000 | $1.00 | $90.0K | 90.0K | Form 4 ↗ |
Kim Jiny director | Aug 8, 2025 | Award | 22,000 | $1.00 | $22.0K | 22.0K | Form 4 ↗ |
Capponi Vincent President and COO | Aug 8, 2025 | Award | 89,100 | — | — | 766.3K | Form 4 ↗ |
Capponi Vincent President and COO | Aug 8, 2025 | Award | 111,100 | $1.00 | $111.1K | 111.1K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Cytosorbents Corporation (CTSO) is primarily owned by institutional investors, who hold approximately 26.3% of total shares outstanding. Company insiders own approximately 12.26%, while retail and public investors account for the remaining 61.45%.
The largest institutional shareholder of Cytosorbents Corporation is AVENIR CORP, holding approximately 5.08 million shares — equal to 8.12% of outstanding shares — as of September 30, 2025.
A total of 50 institutional investors currently hold CTSO stock, with a combined institutional value of approximately $15,417,218 as of the most recent 13F filing period.
Frequently asked questions
CTSO ownershipCytosorbents Corporation (CTSO) is primarily owned by institutional investors, who hold approximately 26.3% of shares. The largest shareholder is AVENIR CORP with a 8.12% stake. Company insiders hold 12.26%. Data sourced from SEC Form 13F as of September 30, 2025.