If you are certain that the returns on any investment will be very low during the next 20 years, presumably you could make a lot of money by using some sort of

If you are certain that the returns on any investment will be very low during the next 20 years, presumably you could make a lot of money by using some sort of long-term options strategy. Why won't you just do that? (I'd actually strongly advise against this, I'm just attempting to prove a point). There is no way of knowing what the future will hold other than attempting to extrapolate from the past. Besides, if the future is going to be as poor as you seem to expect, you're screwed regardless of how you position yourself.