What is the name of the founder who sold his stake in Apple early on?

The Apple co-founder who sold his stake early was Ronald Wayne.

Wayne helped found Apple Computer alongside Steve Jobs and Steve Wozniak in April 1976. He held a 10 percent stake and contributed adult business experience, including drafting an early partnership agreement and designing Apple's first logo. However, he soon became concerned about personal financial exposure because company debts could potentially affect the founders personally.

On April 12, 1976, only 12 days after Apple was formed, Wayne sold his shares back to Jobs and Wozniak for $800. He later received an additional $1,500 to relinquish any future claims. His decision is often described as one of history's most expensive early stock sales, because that 10 percent stake would eventually have been worth billions. Still, Wayne has said that leaving made sense for his circumstances at the time. Mike Markkula was an early investor and executive, not the founder associated with this sale.