First increase your market share by advertising bleeding edge segregated wallets that "exceed" hot/cold wallet security, and claim that all user funds are insured and website is unhackable due to multisig wallet where another company and customer hold the other keys
Short sell bitcoin.
Announce that you have been hacked for one percent of all bitcoin in circulation.
As market crashes, buy back bitcoin at lower price.
Settle customer accounts at higher price at time of "hack".
Give USD denominated debt tokens in exchange for "lost" funds. Incentivize victims to stay quiet with promise of being made whole in the future
Socialize losses even - to avoid lawyers and accountants and public disclosures and bankruptcy - despite the advertised "segregated" wallets.
Pay back debt after price of stolen bitcoin increases from deflation/scaling/adoption.
Use hacked KYC documents to create accounts on other exchanges with stolen identities.
Move funds in and out of altcoins - especially the new censorship resistant ETC fork.
Eat your cake and have it too.
If you get caught just leave the country with fake papers. Stolen Bitcoin and customer KYC documents can buy many fake documents in trade.
Kind of makes insider trading look benign in comparison.
It's a genius scam I will admit. Bitfinex will go down as the most well thought out scam in history.