Many lessons were learned, though some – such as the danger of storing significant amounts of cryptocurrency on centralized exchanges – were not.
source https://www.google.com/url?rct=j&sa=t&url=https://www.ccn.com/5-years-mt-gox-bitcoin-exchange-collapse&ct=ga&cd=CAIyGmM2Nzk3ODA2ZWViNjVjODI6Y29tOmVuOlVT&usg=AFQjCNGX2MSeP6GmDMkunZRD5QTbpLDg5w