Josh Brolin trades on his experiences for Wall Street role

It was Josh Brolin's father who warned him: "You've got to have a back-up, so stay in school and have something to fall back on." Fortunately, the star of the upcoming Wall Street: Money Never Sleeps took Brolin Snr's advice and, in 2005, decided to sell his family ranch in Paso Robles, California, and start an online trading website.

"I didn't like the films I was doing," he says. "And I wasn't making a lot of money anyway. I said: 'I'd rather do something else than act in the stuff that I'm acting in. I'll do theatre and things that I like that nobody will see. But that's OK, as I hate these movies and I'm not interested.'"

Already a seasoned day-trader – a common occupation where stocks are bought and sold before the market closes for the day – Brolin offered investors five- to ten-day "stock baskets" based on trends and the current state of the market.

"I learned an incredible amount of discipline doing it," he admits, though he confesses it has its dangerous side. "It's almost like gambling."

Brolin dismisses the idea that his trading experiences were useful in understanding his character in Wall Street: Money Never Sleeps. He plays Bretton James, a billionaire hedge-fund manager who has supplanted the ailing corporate raider Gordon Gekko (Michael Douglas, reprising his role from the 1987 original) as Wall Street's villain.

"I knew the world but I didn't know the world of big money," he says. "High finance is a very different thing."

'Wall Street: Money Never Sleeps' is in cinemas nationwide.