Hackers are evolving faster than technology, people are aware that data breaches and loss of funds are becoming more frequent due to cyber-attacks.

Simple bugs can lead to the user having to pay the higher taker fee instead of the maker fee, transactions that aren’t recorded properly in the ledger or larger bugs can also lead to temporary trading stops.

It is common practice for traditional exchanges to keep fractional reserves. Similar to a bank run on a traditional bank. With more and more people withdrawing from an exchange the likelihood of the business actually becoming insolvent increases.