Elon Musk made a $6 billion mistake when he bought SolarCity with Tesla stock

Elon Musk made a $6 billion error when he used Tesla stock to buy SolarCity in 2016.
The shares were worth $2.6 billion at the time, but have soared 320% since then.
Musk effectively paid $8.4 billion for SolarCity, more than triple what he planned to spend.
Warren Buffett made the same error when he used shares to buy Dexter Shoe in 1993.
Visit Business Insider's homepage for more stories.When Elon Musk acquired SolarCity in the fall of 2016, he paid for it using Tesla stock worth $2.6 billion