Please review these arbitraging strategies and expose any flaws. The "market makers" here just convert 1 currency to another at their exchange rate. They are not forex "trading" houses per se. So I do not enter and exit with the same MM. Assumed required criteria: 1) Market maker #1 "MM1" has a lower buy price for currency 1 "C1" bought with currency 2 "C2" than market maker #2 "MM2" has as their sell price for the same instrument. 2) All accounts with banks "BA#" and market makers would be in my name. 3) MM1 should not know that I also deal with MM2 (and/or vice versa) or they may change their prices to not have this imbalance. (Or is this impossible because my relationships will show on a credit report check?) 4) This is not laundering because this is not illegal (or is this the very definition of laundering -- "who knows whom" and is this act illegal)? 5) The lot size would need to be large enough to cover (wire) transfer fees "W#" and earn a profit. 6) A bank only deals in 1 currency or their exchange rate will nullify the arbitrage opportunity (or more likely cause a loss in my profits). Method 1: No entity (BA# or MM#) "knows" more than 2 other entities: C1 banks do not know C2 banks and MM1 does not know MM2. BA1 sends W1 in C1 to buy C2 from MM1. MM1 sends W2 in C2 to BA2. BA2 sends W3 in C2 to BA3. BA3 sends W4 in C2 to sell to MM2 and receive C1. MM2 sends W5 in C1 to BA4. BA4 sends W6 in C1 to BA1. Method 2: Each bank "knows" both market makers and each MM knows both banks. But neither bank knows the other bank and neither MM knows the other MM. BA1 sends W1 in C1 to buy C2 from MM1. MM1 sends W2 in C2 to BA2. BA2 sends W3 in C2 to sell to MM2 and receive C1. MM2 sends W4 in C1 to BA1. I haven't done the calculations yet, but what lot size would be required to break even or profit from what difference in buy/sell prices?