Of course they don't store a huge sum in a hotwallet.
They can rollback LTC trading, hoping they can rollback BTC aswel (ofcourse stamp is a problem).
They can rollback LTC trading, hoping they can rollback BTC aswel (ofcourse stamp is a problem).
Well, consider whatever amount withdrawn lost.
They cannot roll back the trades of LTC that have been withdrawn.
Bitfinex will most likely cover these losses so no need for us to worry.
Hopefully no more than a few days. When Gox had their problem, they intially said that trades would be rolled back and trading resumed the following day. However there was also a database leak of all customers usernames, email addresses and hashed passwords at the time, which meant that Gox had no choice but to take the site down and customers had to claim their accounts through a verification process and change their passwords to a secure one. The lengthy process in verifying thousands of accounts meant that trading didn't resume until one week later.
In the case of Bitfinex, it seems there hasn't been any database leaks, so an accounts claims process is probably not needed. But some security issues or bugs within the site may have to be addressed first before normal trading can resume. I am guessing that the recent upgrades to the site in the last week had caused a bug/security vulnerability.
Hopefully we will get a statement from Bitfinex soon.
