A rational person isn't willing to pay more than the present value of future cash flows. Just like how a rational person wouldn't pay $101 for a $100 bill.
Where it gets fun is that: (1) we have people selling $100 bills for more than $100 and, (2) we have people gladly buying $100 bills for more than $100.
Where it gets fun is that: (1) we have people selling $100 bills for more than $100 and, (2) we have people gladly buying $100 bills for more than $100.