Quote from NZDSPeCIALISt:
Not possible. Even if you had 30 10 billion$ accounts (with different prime brokers/banks etc) and simultaneously (say within 3 minutes) bought or sold $200 bill (@20:1 leverage) in cable - you would seriously not be able to offload such a trade unless you moved the market 100 pips (remember cable has about 250b.$ a day turnover (half of it in spot). Soros did something like this is '92 (smaller scale) and if you thought that cable was going to surge/tank then it would be worth it.. In this situation I would set up my own bank and credit lines and get an EBS/reuters acc. for myself