Maybe they've all stopped trading because they realise the only way they are going win is not to trade.
Personally I can't believe they'd even try this. Any experienced trader would know you can't teach newbies to trade successfully in such a short time. Perhaps if they took on 1000 candidates then a few would make a lot of money - by chance. But only 8 - pretty low odds in my opinion.
You can't replace the experience of making mistakes, taking losses and witnessing live price action first hand that seems to be moving in defiance of common sense.
I think city index could come out of this looking pretty bad.