F.I.R.E. Financial Independence Retire Early - Is it a Good Idea?

Have you heard of someone in the FIRE movement? Financial Independence Retire Early is a financial planning system that has been around a while but is getting new life as another generation tries to hack retirement.

Saving up to 50% of their gross pay, millennials and others are cutting back, cutting down and doubling and tripling up on stashing cash in hopes of retiring by 40 years old. The idea is to save to the point that you can withdraw 4% without touching your principal...and that the 4% you draw will be enough to live on without working. In the link above, hear from those who think its a great idea and those who say F.I.R.E. will burn you.