On the surface due to the lack of transparency and gregs stance on btct's closure, this is confirmed a scam.

Hypothetically, say you:
1) take 2000BTC from the BTC community.
2) Let it sit in a wallet for a month.
3) Announce that 25% has been lost due to trading.
4) Give back 1500BTC to the community and keep 500BTC for yourself.
5) go pay off your mortgage

Anyone can do this. This greg guy just happens to be good at writing which made people think he's a smart and trustworthy guy. He is smart!
Trustworthy? how the fuck should we know?!?!?! have you met the guy? NO

If he does not move the fund to another exchange or reveal exactly where the BTC went. this is confirmed a SCAM.
(even if he does reveal where it went. can we trust him? NO)

Disagree with me if you like. But this is how i see it. no fancy words. no bullshit. facts.