January 2015. I would do my best to put paychecks away for a few months coupled with what I already had, and invest it all in Bitcoin in August/September when it was $200. Even if I just let it ride until November 2021 rather than playing the ups and downs I'm looking at a 340x return. If I emptied out my savings and 401k, even if I couldn't convince family members, I'd have tens of millions of dollars.