My understanding was that bankruptcy protection was similar to chapter 11 protection in the US, which allows for continued trading and restructuring. Is that not the case?
If it is the case, that is very different from just the connotations of "bankruptcy" which would be an admission that it is all over now.
(though I guess even if it is like chapter 11 it could well still all be over as they may never come up with a suitable plan)
Is it different in Japan?
"Bankruptcy" in Japan implies liquidation. There are other forms of insolvency which imply an attempt at restructuring (the magic word is "rehabilitation"). It's not clear exactly what's going on. Some people claim that the words "civil rehabilitation" were mentioned in the press conference but it's difficult to imagine how it would even be possible/approved with such a huge shortfall of funds (a total of 870,000 BTC plus $63.6 million in cash that we know of so far).
Hopefully the financial media will clarify things over the next couple of days. Perhaps for some strange reason the "stolen" BTC aren't being regarded as a debt in the insolvency.
As btc is not recognized as legal tender that could well be the case.