Direct answer to the question
“In forex,” “when to buy and sell” is the timing of entering and exiting a currency trade. In a market buy context, it means placing a buy order that executes immediately when the broker receives it, using the best available price at that moment. There is no universally correct timing rule that guarantees outcomes; decisions must be based on verifiable criteria you define in advance.
How market buy timing works
A market buy is an order to buy a currency pair using market pricing rather than a specific target price. Once submitted, it is executed right away at the best available liquidity price.
Because execution happens immediately, the “when” has two practical dimensions:
- Order entry time: the moment you submit the order.
- Execution price time: the moment the broker matches your order with available quotes.
This creates an important distinction for expectations: you may reference a price you saw earlier, but the actual fill can differ due to normal price movement and quote availability between your observation and your execution.
Example checks for choosing entry and exit timing
To keep “when to buy and sell” independent of predictions, use checks that can be verified after execution:
Entry timing checks (buy)
- Confirm the order type is market buy so it executes on arrival.
- Record the reference price you observed (for your own comparison), then compare it to the actual fill price shown in your execution statement.
Exit timing checks (sell)
- Define an exit condition in advance (for example, a time-based rule or a change relative to your own reference level).
- After placing a sell (which may also be a market sell or a different order type), verify what price you actually received in the execution report.
What to compare
At minimum, compare: (a) the reference price you used to decide timing, and (b) the filled price shown by your broker. If they differ, that difference is evidence of execution timing and market movement effects.
Limitations and risks (what you cannot assume)
- No guaranteed results: Forex markets fluctuate, and immediate execution does not remove uncertainty.
- Price slippage risk: With market execution, the final price can be worse or better than a prior reference due to changing quotes.
- Lack of universal timing rules: “When” is partly about your strategy and constraints, not a single fixed calendar or signal.
- No real-time certainty: If you cannot verify live conditions and your actual executions, you cannot confirm whether the timing matched your plan.
Comparison: two common timing approaches
| Criterion | Timed plan (you define) | Reactive timing (based on perceived changes) |
|---|---|---|
| What “when” means | Order entry and exit are triggered by your rules | Order entry and exit depend on what you notice at decision time |
| Verification method | Compare executions to your planned trigger and reference | Compare executions to your observed condition and the fill record |
| Key limitation | Rules may not align with market movement | Perceptions can be late or mismatched to execution price |
| Execution impact (market buy) | Still executed immediately at best available quote | Still executed immediately; perceived change may shift price before fill |