How Does the Concept of ‘Time Value of Money’ Apply to an Attacker’s Cost of a Prolonged 51% Attack?

The attacker's cost is not static; it includes the opportunity cost and the time-dependent expense of renting hash power. A prolonged attack means the attacker is continuously paying for hash rate rental and electricity, which is a significant cash drain.

Furthermore, the longer the attack takes, the greater the risk of detection and counter-measures. The time value of money dictates that the immediate profit must be weighed against the increasing, time-sensitive cost of sustaining the attack, making quick, short attacks more economically viable.