Hello! FXOpen is recognized for providing Straight Through Processing (STP) accounts, allowing direct trade execution with liquidity providers. However, details about the specific liquidity providers might vary and may not be disclosed publicly by the broker. Regarding STP features, you get to observe actual market prices, and the spread (the gap between buying and selling prices) can adjust based on market conditions. (read : Your Definitive Guide to FXOpen ECN Account)

Regarding Flexible Spreads, the spread isn't fixed; it can vary, especially during busy market times, potentially becoming narrower when many people are trading. Furthermore, your orders are executed promptly at the best available price, ensuring you won't encounter a broker refusing to fill your order at your desired price.

In the case of STP brokers like FXOpen, liquidity providers typically include banks, financial institutions, and other entities in the forex market. These providers contribute to a liquidity pool, allowing traders to carry out their trades effectively.