Ask HN: How can I make $50k in 4 months?

somewhat similar from two weeks ago "Ask HN: How to make an extra $50k+ per year without changing jobs?" https://news.ycombinator.com/item?id=30322965

I suppose the easiest is to find a job that pays 150k/year.

But more seriously, you could flip houses if you have enough capital or access to it. This is not surefire at all, though.