Cytosorbents

CTSO on Nasdaq. CytoSorbents sells blood purification devices to hospitals for intensive care and heart surgery patients. Market value $285m.

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Price checks use the past 12 months to June 2026. Quality checks use five annual reports, the latest for the year to December 2025.

Should I look at this?

Look carefully before going further

Read the warning sign in its own filings

This is not advice. Check the numbers below.

Compare with another stock

Cash yield
past 12 months to June 2026
-3.6%low

For every $100 of what the whole company costs, it produced $-3.59 of spare cash in the past 12 months. A savings account pays about $4.

Price to profit
past 12 months to June 2026
n/a

The filings do not give us enough to work this out.

Return on capital
five annual reports to December 2025
-104.0%five-year median

Each dollar kept in the business earns -104 cents a year. Above 10 is good.

Quality score: 1 of 100. Price score: 0 of 100. Our list needs 70 on quality and 60 on price.

$4.12 a share, 45% above its 1-year low

Over the past year the price has ranged from $2.84 to $17.00.

Pays no dividend

Prices from Monday’s close (2 November).

Five years of cash, in billions

-0.0
-0.0
-0.0
-0.0
-0.0
-0.0
2021202220232024202512 monthsto Jun '26
Revenue
$43m$35m$31m$36m$37m
Operating margin
-52.7%-90.9%-102.8%-46.2%-39.8%
Debt to equity
n/a0.140.211.262.82
Shares outstanding
0.04bn0.04bn0.05bn0.06bn0.06bn

Health checks

  • Free cash flow positive0 of 5 years
  • Accounting checksSkipped: company is not yet profitable
  • Debt2.82× equity
  • Revenue growth, five yearsShrinking, 2.0% a year
  • Buying back its own sharesNo, 44% more shares since 2021

The quarter to June 2026

How the business did, compared with the same quarter a year earlier.

  • Sales: $10 million last quarter, about the same as a year ago.
  • A loss of $4 million, after a profit of $2 million a year ago.
  • It loses 35 cents on each $1 of sales, compared with 44 cents a year earlier.
  • Over the past 12 months it spent $9 million more cash than it brought in, compared with $10 million a year earlier.
  • 6% fewer shares than a year ago. Each share owns a bit more of the company.
  • Debt is $13 million more than cash, up from $4 million a year ago.
  • Sales grew on a year ago in each of the last 4 quarters.
Sales by quarter
Sales by quarter
Quarter toAmount
September 2024$9m
December 2024$9m
March 2025$9m
June 2025$10m
September 2025$9m
December 2025$9m
March 2026$9m
June 2026$10m
Profit by quarter
Profit by quarter
Quarter toAmount
September 2024-$3m
December 2024-$8m
March 2025-$1m
June 2025$2m
September 2025-$3m
December 2025-$5m
March 2026-$5m
June 2026-$4m

From the company's quarterly reports to the SEC.

Dates

Next results (estimated)
n/a
Last annual report (10-K)
30 March 2026
Next quarterly (estimated, 10-Q)
5 November 2026

Who owns it

We don't have fund holdings for this stock yet.

Big holders and activists

3 investors own more than 5%.

  • AVENIR CORP
    Passive investor
    at least 8.3%+2.6 pts
    (filed with 1 related holder)
    Since 31 December 2025
  • Thomas A. Satterfield, Jr.
    Passive investor
    6.6%
    Since 13 January 2025
  • Avenue Capital Management II, L.P.
    Passive investor
    at least 5.7%
    (filed with 7 related holders)
    Since 26 June 2024
  • Skylands Capital, LLC
    Passive investor
    Sold down below 5%
    Since 31 March 2025
  • The Vanguard Group
    Passive investor
    Sold down below 5%
    Since 31 March 2025

From Schedule 13D and 13G filings: anyone owning more than 5% must file one.

What insiders did

In the last 12 months, 4 insiders bought $269,332 of shares on the open market.

Cluster buy3 insiders bought within 30 days (4 September 2026 to 15 September 2026).
  • Chan Phillip P.
    Chief Executive Officer, Director
    Bought
    Date
    15 September 2026
    Shares
    3,774
    Price
    $6.00
    Value
    $22,644
  • Sobel Alan D.
    Director
    Bought
    Date
    15 September 2026
    Shares
    2,500
    Price
    $6.10
    Value
    $15,254
  • Capponi Vincent
    President and COO
    Bought
    Date
    14 September 2026
    Shares
    2,073
    Price
    $6.05
    Value
    $12,537
  • Chan Phillip P.
    Chief Executive Officer, Director
    Bought
    Date
    4 September 2026
    Shares
    200,000
    Price
    $0.35
    Value
    $70,000
  • MARIANI PETER J
    Chief Financial Officer
    Bought
    Date
    15 June 2026
    Shares
    100,000
    Price
    $0.44
    Value
    $44,000
  • Chan Phillip P.
    Chief Executive Officer, Director
    Bought
    Date
    15 June 2026
    Shares
    10,333
    Price
    $0.43
    Value
    $4,443
  • Chan Phillip P.
    Chief Executive Officer, Director
    Bought
    Date
    12 June 2026
    Shares
    251,136
    Price
    $0.40
    Value
    $100,454

From Form 4 filings: insiders must report trades in their own company's shares within two days.

Warning signs in its filings

Problems the company itself reported to the SEC, in its own words.

3 serious warning signs in Cytosorbents’ filings.

We look for five warning signs: doubt it can keep going, weak checks on its own accounts, a notice that its past accounts can't be relied on, a change of auditor, and one customer bringing in a big share of sales. We don't check lawsuits, investigations or debt yet.

We checked the auditor's report, internal controls, restatement notices, auditor changes and big customers in the 10-K filed 30 Mar 2026, plus the 10-Q filed 6 Aug 2026 and 9 later 8-Ks.

  • Doubt it can keep going

    Serious

    The company or its auditor warned it may not have enough money to last the next year.

    “These cash and restricted cash balances considered with the Company’s historical and expected future cash used in operations, notwithstanding the Company’s Strategic Workforce and Cost Reduction Plan (see Note 11, “Restructuring”) and the impact of the Amended Loan and Security Agreement (see Note 6, “Long-Term Debt”) raises substantial doubt about the Company’s ability to continue as a going concern within twelve months after the date that the accompanying condensed consolidated financial statements are issued.”
    Show the full paragraph
    As of June 30, 2026, the Company’s total cash and cash equivalents and restricted cash was approximately $ 5.9 million, with $ 1.5 million classified as restricted, and $ 4.4 million as unrestricted and available to fund operations. These cash and restricted cash balances considered with the Company’s historical and expected future cash used in operations, notwithstanding the Company’s Strategic Workforce and Cost Reduction Plan (see Note 11, “Restructuring”) and the impact of the Amended Loan and Security Agreement (see Note 6, “Long-Term Debt”) raises substantial doubt about the Company’s ability to continue as a going concern within twelve months after the date that the accompanying condensed consolidated financial statements are issued.

    From the 10-Q filed 6 August 2026, Part I, Item 1. Financial Statements. Read it in the filing

  • Weak checks on its own accounts

    Serious

    The company said its checks on its own accounts did not work at the end of its latest quarter. Mistakes could slip into the numbers.

    “Based upon that evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that our disclosure controls and procedures were not effective as of June 30, 2026 because of the material weaknesses identified in our internal controls over financial reporting, which are being actively remediated (see below).”
    Show the full paragraph
    Under the supervision and with the participation of our management, including our principal executive officer and principal financial officer, as of the end of the period covered by this report, we conducted an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures, as defined in Rules 13a-15(f) and 15d-15(f) under the Securities Act of 1934. Our disclosure controls and procedures are designed to provide reasonable assurance that the information required to be included in our SEC reports is recorded, processed, summarized and reported within the time periods specified in SEC rules and forms, relating to the Company, including our consolidated subsidiaries, and was made known to them by others within those entities, particularly during the period when this report was being prepared. Based upon that evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that our disclosure controls and procedures were not effective as of June 30, 2026 because of the material weaknesses identified in our internal controls over financial reporting, which are being actively remediated (see below).

    From the 10-Q filed 6 August 2026, Part I, Item 4. Controls and Procedures. Read it in the filing

  • Its past accounts can't be relied on

    Serious

    It told the SEC its earlier accounts should no longer be relied on, usually because they contained errors.

    8-K Item 4.02 filed 31 Mar 2025: the company said its earlier financial statements should no longer be relied on.

    From an 8-K filed 31 March 2025: Previously issued accounts should no longer be relied on. Open the filing

A 10-K is the yearly report every US company files with the SEC. An 8-K is a short notice of a big event.

What could go wrong

  • It carries a lot of debt: 2.8× its equity.
  • Sales have shrunk: 2.0% a year.

Whether the price already reflects the risks is what the deep dive is for.

The deep dive

Everything above is arithmetic on public filings. The deep dive reads the last ten years of annual reports, the proxy statements, and the earnings calls, then argues the case the way Buffett, Klarman, and Hohn would, and checks every claim against the source.

  • What the business is worth, as a range, and the margin of safety at today’s price
  • Prices to start buying, buy, and buy hard
  • The three things that would make this a mistake
  • Every number footnoted to the filing it came from
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What a finished deep dive looks like

Not advice. Numbers on this page come from SEC filings and are updated each night; prices are updated again after the US market closes. The five-year figures are rounded.