Likely this is related to the marshmallow. I need to eat. I will eat it now. I cannot guarantee the marginal return on more marshmallows. I mean maybe if real life was like "wait one minute and double your money" people would do it, but typically it's like, lock up your cash for weeks, months, years at a time for margins, not for doubling your marshmallow count.

In real life, realized savings or gains of 1 or 2 or 4 percent for a 6 month wait is not worth the RISK of locking up that marshmallow (or T-bond) when having that marshmallow locked up may result in say, no housing.