The world of finance is living in “exponential” times, said John Sculley.

John Sculley, former chief executive officer of Apple AAPL 0.04% , offered some words of wisdom to big financial firms at the Money20/20 fintech conference in Las Vegas on Sunday night: plan for radical change, or prepare for obsolescence. (You can read Fortune’s recent exclusive Q&A with Sculley here.)

Taking the stage after awards for a “hackathon” were doled out to competing teams of developers, Sculley told the audience that financial incumbents are in a race for their lives—and that the race is a sprint. In issuing the warning, the former president of PepsiCo PEP -0.18% said that the world of finance is presently living in “exponential” times, rather than “linear” ones.

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“If you think in the fintech world that you can live in linear times,” Sculley said, characterizing the attitude as having a “sit-back-and-wait” mentality, “it ain’t going to turn out that way.”

The onetime successor to Apple founder Steve Jobs cited Kodak KODK -2.99% , the once high-flying photography company that struggled to remain relevant once digital photo technology burst onto the scene, as a prime example of failure to keep up with exponential times. “There will be Kodak examples in the financial services industry,” he warned members of the audience, many of whom represented big banks and startups.