Kriyas Yam Suf or Har Sinai would be nice, but we’re addicted to modern technology (indoor plumbing, anti-biotics, pain killers, refrigeration, etc.).
If you buy the the low date before the Great Depression (in 1932), you have to wait a long time to max your profits (and the period of 1932-1948 is one period worth avoiding). If you buy in March 2009 and sell in September 2018, you maked a quick killing with the privations of the pre-tech world.
@Joseph But then you won’t have bechira in Galus since you saw a neis nigla and you’ll never get schar for any mitzva that you do for the rest of your life!