It’s also important to know that FX brokers who advertise small spreads will probably have a “liquidity provider”, which is a dealer or MM. The fine print will often reveal that the advertised spread is only available in certain market conditions, I.e, low volatility. These liquidity providers are 3rd parties and have the capacity to widen the spread at will. FX brokers will reveal in the fine print that they must mover the spread onto their clients (retail traders). Retail traders pay the difference in the spread, and the MMs, Dealers and brokers will make an “OTC gain” from taking the other side of the retail traders positions as less than half of these positions are profitable.