C3is completes 1-for-40 reverse stock split

Rhea-AI Filing Summary

C3is Inc. (CISS) implemented a one-for-40 reverse stock split of its common stock effective as of 11:59 p.m. Eastern time on August 18, 2026. The number of outstanding common shares was reduced from approximately 57.6 million to approximately 1.44 million, while the $0.01 par value and other terms of the common stock were unchanged. Shares began trading on a split-adjusted basis on the Nasdaq Capital Market on August 19, 2026 under the symbol CISS. No fractional shares were issued; holders instead received cash in lieu of fractional shares. Outstanding warrants and Series A Convertible Preferred Stock will be proportionately adjusted for exercise and conversion terms, with certain warrant exercise and conversion prices further adjusted to the lowest daily volume weighted average price over a specified 10-trading-day window around the effective date.

Filing Explained

The filing adds that two registration statements incorporate the report and that warrant adjustments preserve original aggregate exercise-price terms.

The reverse split is complete, and this Form 6-K is incorporated by reference into the company’s Form S-8 and Form F-3 registration statements.

A reverse split consolidates shares and raises the per-share price proportionally; the supplied definition says the split itself does not change company value.

For the specified warrants, the filing preserves an alternative zero-cash exercise exchange option for the Class B-1 and C-1 warrants and adjusts issuable shares so the aggregate exercise price at original issuance remains unchanged.

The further adjustment to warrant exercise prices and the Series A Convertible Preferred Stock conversion price remains tied to the lowest daily volume-weighted average price during the five-trading-day-before and five-trading-day-after window.

Key Figures

Reverse split ratio: one-for-40 Shares outstanding before split: approximately 57.6 million shares Shares outstanding after split: approximately 1.44 million shares +3 more

6 metrics

Reverse split ratio one-for-40 Reverse stock split of common stock effective August 18, 2026

Shares outstanding before split approximately 57.6 million shares Common stock outstanding prior to the one-for-40 reverse stock split

Shares outstanding after split approximately 1.44 million shares Common stock outstanding following the one-for-40 reverse stock split

Par value per share $0.01 per share Par value of C3is Inc. common stock, unchanged by the reverse split

Trading start date post-split August 19, 2026 Date common stock began trading on a split-adjusted basis on Nasdaq Capital Market

VWAP adjustment window five trading days before and five trading days after Period used to adjust certain warrant exercise and conversion prices to lowest daily VWAP

Key Terms

reverse stock split, par value, volume weighted average price, alternative zero cash exercise exchange option, +1 more

5 terms

reverse stock split financial

"effectuate a reverse stock split of the Company’s issued and outstanding shares"

A reverse stock split reduces a company's number of outstanding shares while raising the price per share proportionally, so the total value of each investor's holding is unchanged; a 1-for-10 split turns 100 shares worth $1 each into 10 shares worth $10 each. Companies often do this to regain compliance with an exchange's minimum price rule or to attract investors who avoid very low-priced stocks.

par value financial

"common stock, par value of $0.01 per share"

Par value is the fixed amount printed on a bond or stock that represents its original value when issued. It’s like the face value of a coin or bill—what the issuer promises to pay back or the starting price of a stock—though it often doesn’t change with market prices. It matters because it helps determine certain financial details, like how much the company will pay back at maturity.

volume weighted average price financial

"adjusted to the lowest daily volume weighted average price during the period"

The volume weighted average price (VWAP) is a way to measure the average price of a security, such as a stock, over a specific period, taking into account how many units were traded at each price. It’s similar to calculating the average cost of items bought when some are more frequently purchased than others. Investors use VWAP to assess whether a security is being bought or sold at a fair price during trading.

alternative zero cash exercise exchange option financial

"also being exercisable pursuant to an alternative zero cash exercise exchange option"

convertible preferred stock financial

"The Company’s outstanding warrants and Series A Convertible Preferred Stock will be"

Convertible preferred stock is a special class of company shares that pays priority, usually fixed, payments to holders and can be exchanged later for a set number of common shares. It matters to investors because it combines steady income and added protection with the chance to share in a company’s upside; think of it as a hybrid between a bond that pays regularly and an option to convert into growth-oriented stock, where the conversion rules influence both potential gains and how much common shareholders’ ownership may be reduced.

FAQ

What reverse stock split did C3is Inc. (CISS) execute in August 2026?

C3is Inc. executed a one-for-40 reverse stock split of its common stock, effective at 11:59 p.m. Eastern time on August 18, 2026. This consolidated every 40 pre-split shares into one post-split share without changing the stock’s $0.01 par value or other terms.

How did the C3is Inc. (CISS) reverse split affect common shares outstanding?

The reverse split reduced C3is Inc.’s outstanding common stock from approximately 57.6 million shares to approximately 1.44 million shares. This share count change reflects only a recapitalization; the filing states the par value and other terms of the common stock remain the same.

When did C3is Inc. (CISS) begin trading on a split-adjusted basis?

C3is Inc.’s common stock began trading on a split-adjusted basis on August 19, 2026 on the Nasdaq Capital Market. The company confirms the shares continue trading under the symbol CISS following the one-for-40 reverse stock split.

How did C3is Inc. (CISS) handle fractional shares in the reverse split?

C3is Inc. did not issue fractional shares in the reverse split. Instead, stockholders who would otherwise have held a fractional share of common stock received a cash payment in lieu of that fractional share, according to the company’s disclosure.

What happens to C3is Inc. (CISS) warrants and preferred stock after the reverse split?

Outstanding warrants and Series A Convertible Preferred Stock of C3is Inc. will be proportionately adjusted, increasing exercise or conversion prices and reducing shares issuable. Certain warrant and conversion prices will further adjust to the lowest daily VWAP over a specified 10-trading-day period around the split.

Did the C3is Inc. (CISS) reverse split change the par value of its common stock?

No, the reverse stock split did not change the $0.01 par value of C3is Inc.’s common stock. The company states that the par value and other terms of the shares of common stock were not affected, only the number of shares outstanding was adjusted.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 6-K: How Foreign Companies Report to the SEC →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 08/19/2026 - 04:01 PM Accepted by SEC EDGAR 08/19/2026 - 04:01 PM Learn about SEC filing dates

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of August 2026

Commission File Number 001-41717

C3IS INC.

(Translation of registrant’s name into English)

331 Kifissias Avenue Kifissia 14561 Athens, Greece

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒   Form 40-F ☐

INFORMATION CONTAINED IN THIS FORM 6-K REPORT

Reverse Stock Split

On August 18, 2026, C3is Inc. (the “Company”) filed an amendment to its Restated Articles of Incorporation, to effectuate a reverse stock split of the Company’s issued and outstanding shares of common stock, par value of $0.01 per share. A copy of the amendment is attached hereto as Exhibit 4.1.

Effective as of 11:59 p.m. Eastern time on August 18, 2026, the Company effected a one-for-40 reverse stock split of its shares of common stock, and the Company’s common stock began trading on a split-adjusted basis on The Nasdaq Capital Market as of the opening of trading on August 19, 2026. The reverse stock split reduced the number of outstanding shares of the Company’s common stock from approximately 57.6 million shares to approximately 1.44 million shares and affected all outstanding shares of common stock. No fractional shares were issued in connection with the reverse split. Stockholders who would otherwise hold a fractional share of the Company’s common stock received a cash payment in lieu of such fractional share. The Company’s outstanding warrants and Series A Convertible Preferred Stock will be proportionately adjusted to increase the exercise price and reduce the number of shares issuable upon exercise to reflect the reverse stock split.

The exercise price of the Class B-1, B-2, C-1 and C-2 Warrants, and accordingly the conversion price of the Series A Convertible Preferred Stock, will be further adjusted to the lowest daily volume weighted average price during the period commencing five consecutive trading days immediately preceding and the five consecutive trading days following the effective time of the reverse split (if lower than the then current exercise price), with the Class B-1 and C-1 warrants also being exercisable pursuant to an alternative zero cash exercise exchange option, and the number of shares of common stock issuable upon exercise will be proportionately adjusted such that the aggregate exercise price of such warrants as of their original issuance date will remain unchanged.

The par value and other terms of the Company’s shares of common stock were not affected by the reverse stock split. The Company’s post-reverse split common shares have a new CUSIP number, Y18284409, and continue to trade on the Nasdaq Capital Market under the symbol “CISS”.

A copy of the new form of stock certificate for the Company’s post-reverse stock split shares of common stock is attached hereto as Exhibit 4.2.

*****

This report on Form 6-K is hereby incorporated by reference into the Company’s Registration Statement on Form S-8 (Reg. No. 333-273306) filed with the Securities and Exchange Commission on July 18, 2023 and Registration Statement on Form F-3 (Reg. No. 333- 285135) filed with the Securities and Exchange Commission on February 21, 2025.

EXHIBIT INDEX

4.1		Articles of Amendment to Restated Articles of Incorporation.
4.2		Form of Common Stock Certificate.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: August 19, 2026

C3IS INC.
By:		/s/ Nina Pyndiah
Name:		Nina Pyndiah
Title:		Chief Financial Officer

Filing Exhibits & Attachments

2 documents

Other Documents

• EX-4.1 EX-4.1 7.6 KB
• EX-4.2 EX-4.2 15.8 KB