To be more specific, Tull talked publicly for the first time about what he’s been up to secretly for quite some time. The film producer, whose company was bought by Wanda Group for $3.5 billion earlier this year, already has deployed between $75 million and $100 million into such companies as virtual reality company Oculus (purchased by Facebook (FB)), autonomous auto startup Zoox (where he is a director), media content site Players Tribune, data storage company OpenDrives, and mixed-reality company Magic Leap.

“After talking to my business manager and accountants, we realized that if this were a professionally-managed fund, it would be a decent-sized fund at this point, so we felt we should formalize this,” says Tull, who is naming the firm Tull Investment Group.

He also today announced a new investment in Heal, a provider of on-demand physician house-calls for both adults and children, where Tull will join the company’s board. Tull disbursed around $5 million already, and the company is in the midst of raising a much larger follow-on round.

“My plans have evolved in terms of dollars invested, which means it’s also evolved in terms of my involvement with the companies,” Tull explains. “It’s one thing to throw a million bucks into something early and hope it gets better, but it’s another if you’re doing what I’m doing now, writing substantial checks, leading rounds and being very hands-on.”

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Indeed, Tull says his investment thesis is based not only on technologies and life sciences that he finds interesting, but also ones where he “can put my finger on the scales a bit.”

One area Tull isn’t putting new money, however, is film or similar forms of entertainment. “I have enough exposure already with Legendary, and have scratched that itch,” he says.