No cryptocurrency has ever had a negative price or "fallen below zero," as crypto assets are non-negative by design, prices can't drop below zero on exchanges due to how trading mechanics work.
Notable Price Crashes
The phrase "hero to zero" often describes dramatic collapses like Terra's LUNA token, which fell from over $100 to near $0 in May 2022 amid its UST stablecoin depegging.
LUNA (Terra): Dropped from $116 to $0.0001, wiping out $40+ billion.
Bitcoin (June 2011): Crashed ~99% from $32 to $0.01 after Mt. Gox hack.