Currently, Okeanis Eco Tankers are only listed on the Oslo Bors with ticker OET.
That will be changing - the company has filed with the SEC and is seeking a NYSE listing. Once complete, the company will make the US listing its primary listing, and the Oslo listing a secondary listing - both with ticker ECO
I recall a time when OET had Aframax, Suezmax & VLCC vessels. Seems like now the fleet is only Suezmax (6) and VLCC (8). The founding family is the Alafouzos family who have a majority stake (~57%). It will be nice to have another crude tanker company in the US stock market.