The Fire movement is a growing trend amongst young workers which is growing in popularity thanks to its very enticing goal which is spelled out in the name.
FIRE is an acronym of Financial Independence and Retiring Early. 
The idea is that by following a very aggressive saving and investing strategy people can get to a point where they are effectively retired at a very young age, sometimes younger than 30. 
Getting to that point is harder for some than others, but advocates of the movement argue that this difficulty has more to do with personal lifestyles rather than personal incomes.