Quotes: Compound Interest Time Travel Gambit

Compound interest is the most powerful force in the universe.
falsely attributed to Albert Einstein.

This [sidequest in which the player deposits 5000 rupees] will probably result in a devastating crash of the bank and the complete destabilization of Clock Town's economy, but hey, that still beats being obliterated by a falling moon.
The Legend of Zelda: Majora's Mask Official Strategy Guide, on a sidequest exploiting this trope