Robinhood CEO Vlad Tenev says it's not "entirely relevant" that the trading platform's so-called tokenized shares of OpenAI and SpaceX aren't technically equity in the companies. It comes after OpenAI raised concerns about the product, which is designed to give users in the European Union exposure to various U.S. stocks — including private companies, which are less liquid than publicly listed firms. OpenAI last week warned that Robinhood's stock tokens do not represent equity in the company and said in a post on X that, "any transfer of OpenAI equity requires our approval — we did not approve any transfer." Robinhood says its OpenAI stock tokens are "enabled by Robinhood's ownership stake in a special purpose vehicle." "It is true that these are not technically equity," Tenev, who co-founded Robinhood in 2013 with fellow entrepreneur Baiju Bhatt, told CNBC's "Squawk Box Europe" Tuesday, echoing his initial response to OpenAI's concerns.