John Glencross co-founded Calculus Capital after an earlier career in investment banking. He leads the firm and has direct responsibility for its media investment and media finance activities. On the equity side, Calculus Capital holds investments in a number of UK production companies, including Jude Law's Riff Raff Entertainment, David Abraham's Wonderhood Studios, Brouhaha Entertainment, and Maven Screen Media. Recent productions from this portfolio include the Netflix title Black Rabbit (nominated for a Golden Globe and seven Emmys); Eleanor the Great, Scarlett Johansson's directorial debut; Happy Hours, a trilogy of romantic comedies reuniting Dawson's Creek co-stars Katie Holmes and Josh Jackson; and the television series Power: The Downfall of Huw Edwards.

Calculus Capital also provides secured lending to film and television productions, with finance structured against tax credits, presales, and other contracted revenues, as well as gap finance. Recent transactions include Bill Nighy's &Sons; H is for Hawk, starring Claire Foy; Stuffed, featuring Jodie Comer and Harry Melling which recently premiered at Toronto; and Ish, which won the Audience Choice Award at the Venice Film Festival.

Through this combination of equity investment and structured finance, John Glencross has built a portfolio spanning both the production and financing sides of the film and television industry.