Speed is the name of the game in early retirement, but according to one couple, there’s more to it than that.

Business Insider reported that Kristy Shen and Bryce Leung set a goal to sunset early in 2012. (1) They discovered the Financial Independence, Retire Early (FIRE) movement (2), which has the goal of retiring before the expected age of 65. The couple came across a strategy that claimed this was possible by investing in index funds.

Initially skeptical, they ran the numbers and realized they could retire on a modest $1,000,000 portfolio. By 2015, they had reached their goal. They quit their engineering jobs and began traveling the world, living off their investments. They earned some income from their two…