[8][9] He joined the Ethereum team as one of five original founders with Vitalik Buterin in late 2013[3][10] and held the position of chief executive.

[3][10] In late 2014, Hoskinson and former Ethereum colleague Jeremy Wood formed IOHK (Input Output Hong Kong), an engineering and research company, to build cryptocurrencies and blockchains.

[8] IOHK's key project is Cardano, a public blockchain and smart contract platform that hosts the ADA cryptocurrency.

[18][19] Hoskinson contributed $1.5 million to fund a 2023 Galileo Project expedition led by astronomer and "alien hunter" Avi Loeb to explore debris from the meteorite CNEOS 2014-01-08 (also called IM1) that crashed into the Pacific Ocean in 2014.

[20][21][22] Loeb argued that this object could have been created by alien life, an idea that lacked widespread support from the scientific community.

[24] [25] However, a paper published by the American Astronomical Society In October showed that the chemical compositions provided by Loeb’s analysis most closely matched human-produced coal ash.

[32] In May 2024, Slate magazine reported that Hoskinson was one of the technology and finance "disrupters" who were backing Robert F. Kennedy Jr.'s 2024 presidential campaign.