2017-2018 Cryptocurrency Crash: Between December 2017 and February 2018, the value of cryptocurrencies like Bitcoin, Ethereum, and Ripple dropped significantly. At its peak in December 2017, Bitcoin was worth almost $20,000. However, by February 2018, its value had dropped to around $7,000. This crash was caused by a combination of factors, including increased regulation, security concerns, and a general cooling off of the hype that had driven the cryptocurrency market to unprecedented highs.

2013 Bitcoin Crash: In April 2013, the value of Bitcoin fell by over 70% in just a few days, from a high of around $260 to a low of $50. This crash was triggered by a combination of factors, including a wave of panic selling and the hacking of the popular Bitcoin exchange Mt. Gox, which lost around 850,000 Bitcoins (worth around $450 million at the time) in a massive security breach.

Black Thursday, March 2020: The third largest cryptocurrency crash occurred in March 2020 when the value of Bitcoin fell by around 50% in just 24 hours, and the cryptocurrency market as a whole lost almost $100 billion in value. This crash was caused by a combination of factors, including the impact of the COVID-19 pandemic on global markets, as well as concerns about the overall stability and security of the cryptocurrency market.