Spreads, liquidity and the price you actually get

Two prices, not one

Imagine walking into a currency exchange and seeing one price for buying euros and another for selling them. A trading quote follows the same two-sided logic. The bid is the price available to someone selling; the ask is available to someone buying. Their difference is the spread. A midpoint chart sits between them, but a midpoint is not necessarily a tradable price.

Spreads compensate liquidity providers for several things, including inventory risk and the possibility that the person trading with them has newer information. They are not simply a fixed toll. When uncertainty increases or competition decreases, a provider may widen a quote or reduce the size available. Conditions that looked inexpensive a few moments earlier can change abruptly.

When a model starts from midpoint prices, the spread cost is half the entry spread plus half the exit spread for a buy-then-sell round trip, assuming symmetric quotes around those midpoints. A one-pip spread on entry and a three-pip spread on exit therefore cost two pips relative to the midpoint path. Subtracting 'one spread' is exact only when the assumed entry and exit spreads match. Using actual ask-entry and bid-exit fills already captures this difference.

Liquidity includes quantity

A quote is only useful together with an amount. A small transaction may execute at the best displayed price while a larger transaction uses several prices. The weighted-average fill is then less favorable than the headline quote. This effect is one reason trading costs can increase with size even if the commission schedule is unchanged.

Retail OTC forex does not present one universal exchange order book covering the entire market. Providers can use different sources and execution arrangements. Comparing two screenshots without their timestamps, quote sides and order sizes can produce a false accusation of an error. Meaningful comparison requires matching those details and understanding each provider's price policy.

Consider a hypothetical buy of €20,000. If €5,000 is available at 1.1000 and the remaining €15,000 fills at 1.1004, the weighted-average price is 1.1003. That is three pips worse than the best displayed ask, or $6 more on the full amount. The best quote was real but insufficient for the order. A depth assumption belongs beside every simulated fill whose size could exceed the quantity available at the headline price.

Busy does not always mean easy

Major financial centers create recurring patterns in market participation, but session labels are not guarantees. Holidays, daylight-saving changes, economic releases and unexpected events alter activity. The first instant after an important announcement can be extremely busy and still difficult to trade: quotes are changing quickly and available size may disappear.

Slippage is the difference between the expected execution price and the price received. It may be favorable or unfavorable. A market order prioritizes execution rather than a particular price. A limit order imposes a price boundary but may remain unfilled. Neither removes the economic uncertainty of the position once it exists.

Execution also depends on what counts as a valid price. An indicative quote is not necessarily a firm commitment, and an OTC provider may apply checks or rejection rules under its execution policy. A limit order can be partially filled or remain in a queue while another trader receives a fill. These are distinct outcomes from slippage on a completed market order. A useful log separates orders requested, orders accepted, quantities filled and prices received.

Measure friction before evaluating an idea

A hypothetical method that targets very small price moves can be overwhelmed by spreads and commissions. If average gross gains are only a few pips, a modest deterioration in execution can erase the apparent advantage. Testing the method using midpoint prices and no costs answers a different question from whether a person could implement it.

For an educational observation log, record a consistent pair and hypothetical size at several times. Note bid, ask, spread, scheduled events and whether the quote changed while you wrote it down. This is not a search for a magic trading hour. It is a way to see that market access has variable costs, and that a quiet-looking chart says little about available liquidity. Avoid entering real orders merely to collect observations.

Read the complete schedule

Commission-free is not the same as cost-free. The spread may include a markup, while overnight financing, conversion and withdrawal charges sit elsewhere in the fee schedule. A useful comparison puts every charge into the same reporting currency and holding period. Promotional headlines are not a substitute for that arithmetic.

For a meaningful cost comparison, choose a reference that was observable when the decision was made. The difference between that reference midpoint and the actual fill captures more than the advertised spread: it can include price movement during transmission, limited depth and execution delay. Compare buys and sells with consistent signs, and include rejected or unfilled orders in the record. Looking only at completed orders can hide the cost of opportunities that were never executable.