C3is Inc. (CISS)
Nasdaq: CISS · Deep Sea Foreign Transportation of Freight · Athens, GR · filing with the SEC since 2022
Who owns C3is Inc.
As filed with the SECHolders of 5% or more
8
Imperial Petroleum Inc. holds 80.5% of Common Stock, par value $0.01 per share, as its SCHEDULE 13D/A filed Aug 28, 2026 says.
Directors and officers
5
report now, of 5 people on the record since 2026. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 8 named at left.
Holders of 5% or moreshare of the class, as filed
Imperial Petroleum Inc.
SCHEDULE 13D/A · filed Aug 28, 2026 · Common Stock, par value $0.01 per share · 68.8% in Jul 30, 2026
Lind Global Fund III LP
SCHEDULE 13G · filed Jul 31, 2026 · Common Stock, par value $0.01 per share
Ayrton Capital LLC
SCHEDULE 13G · filed Feb 11, 2026 · Common Stock, par value $0.01 per share
CVI Investments, Inc.
SCHEDULE 13G · filed Aug 3, 2026 · Common Stock, $0.01 par value per share
Horne Timothy P
SCHEDULE 13G · filed Sep 3, 2026 · Common Stock, no par value
Jane Street Group, LLC
SCHEDULE 13G · filed Aug 19, 2026 · common stock, par value $0.01 per share
Wexford Capital LP
SCHEDULE 13G/A · filed Sep 29, 2025 · Common Stock, par value $0.01 per share · 10.2% in Sep 24, 2025
Athanasios Tsiakmakis
SCHEDULE 13G/A · filed Jan 13, 2026 · Common Stock, par value $0.01 per share · 14.4% in Oct 28, 2025
Evergreen Capital Management LLC
SCHEDULE 13G/A · filed May 11, 2026 · Common Stock, par value $0.01 per share · reported falling below 5%, from 9.99% in Jan 14, 2026
Harry N. Vafias
SCHEDULE 13D/A · filed Oct 10, 2025 · Common Stock, par value $0.01 per share · reported falling below 5%, from 6.3% in Oct 1, 2025
Alta Partners LLC
SCHEDULE 13G/A · filed Oct 5, 2026 · Common Stock, par value $0.01 per share · reported falling below 5%, from 8.2% in Aug 3, 2026
Pandora Consultants II SA
SCHEDULE 13G/A · filed Oct 2, 2025 · Common Stock, par value $0.01 per share · reported falling below 5%
L1 Capital Global Opportunities Master Fund, Ltd.
SCHEDULE 13G/A · filed Aug 14, 2026 · Common Stock, $0.01 par value · reported falling below 5%, from 9.99% in Dec 17, 2025
S.H.N. Financial Investments Ltd.
SCHEDULE 13G/A · filed Aug 14, 2026 · Common Shares, par value $0.01 · reported falling below 5%, from 9.99% in Dec 18, 2025
Ascent Partners Fund LLC
SCHEDULE 13G/A · filed Oct 5, 2026 · Common Stock, par value $0.01 per share · reported falling below 5%, from 9.99% in Aug 4, 2026
Towerview LLC
SCHEDULE 13G/A · filed Oct 2, 2026 · Common Stock · reported falling below 5%, from 6.5% in May 18, 2026
What CISS reports owning in othersstakes of 5% or more, and other ties
Other ties the annual report names
Afrapearl II
A company bought · asset acquisition · owns, named in the 20-F filed Apr 22, 2026
Eco Spitfire
A company bought · asset acquisition · owns, named in the 20-F filed Apr 22, 2026
San Remo
A company bought · asset acquisition · owns, named in the 20-F filed Apr 22, 2026
4 subsidiaries in 1 country, from the list filed with the 20-F filed Apr 22, 2026.
Insider tradesForm 4
0sales
0purchases
0sales on a scheduled plan
0people selling
$0sold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Sep 30, 2025 to Sep 30, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
No open-market trade is on the record for these years.
Dollars as filed, summed by the transaction date.
People who traded in the window
No one on the roster filed an open-market trade in the window.