Exactly 5 years ago today (May 19, 2021), the crypto market experienced one of the most brutal panic sells in its history.
Within a few hours, the majority of altcoins crashed dramatically: BTC dropped sharply, while many major altcoins lost between 30% to over 50% of their value almost instantly. The attached chart clearly illustrates the scale of the bloodbath, with dozens of tokens showing red candles of -40% to -90% in a single day.
![[:en]This day in 2021: The biggest Panic Sell in crypto history – A series of altcoins plummeted 30-90% in just a few hours.[:vi]Ngày này năm 2021: Cú Panic Sell lớn nhất lịch sử crypto – Hàng loạt altcoin “bay màu” 30-90% chỉ trong vài giờ[:] 1 photo 2026 05 19 09 40 53](https://onfa.us/wp-content/uploads/2026/05/photo_2026-05-19_09-40-53-181x300.jpg)
That event remains a painful reminder for many veterans of how quickly sentiment can shift and how devastating leveraged liquidations can be. It also marked the beginning of a long bear market that tested the resilience of the entire industry.




