Ethereum’s big software update on 15 September may have turned the second-largest cryptocurrency into a security in the eyes of a top US regulator.

Securities and Exchange Commission chair Gary Gensler said on 15 September that cryptocurrencies and intermediaries that allow holders to “stake” their coins might pass a key test used by courts to determine whether an asset is a security. Known as the Howey test, it examines whether investors expect to earn a return from the work of third parties.