"Billionaire Boys Club" was not well promoted and is considered one of the year's biggest flops, with Egerton upset so few people saw it.
"In some respects the movie didn't turn out as strong as it could have done," he told Entertainment Tonight. "That's me being totally candid. There was a lot of jargon about investments and figures. An audience doesn't go to the cinema for that, they go for character arc...."
"It didn't quite come together in the way it should have, which is really disappointing and horrible for all the talented people who worked on that film."
The movie was released months after details of co-star Spacey's inappropriate behaviour broke, costing the actor his role on "House of Cards" and in Ridley Scott's "All the Money in the World". But "Billionaire Boys Club" had already been shot and edited, so producers had no choice but to release it and hope for the best.
Taron told ET he enjoyed working with Spacey, stating, "He was never inappropriate with me," before adding, "There's a fine line, though, isn't there - between someone being an audacious flirt and being predatory? I thought he was the former. But it's sad that his professional demise threw such a shadow over our film."
Asked to expand on Spacey's behaviour on set, Egerton said, "He's flirty. He is not my first experience of a flirty older bloke."
"Even from the age of 17 or 18, I've experienced that and I've never felt threatened by that, although he (Spacey) obviously has made some people feel threatened, and that's unacceptable."