So do you also execute our trades with the Liquidity Provider, and if yes, so do you own the currency from the underlying market on our behalf?"
We send the trade to the LP to execute, and we hold an account with the LP in the same currency that is used for their margin requirements. So, we do not "own the currency on thier behalf" but we still maintain an account with the LPs to manage the exposure of our clients as all ECN/STP brokers do.