Knowing bid, ask, spread and commissions is essential to measure the true cost of every trade. Regardless of your style —scalping, day trading, or swing—results depend on smart entries/exits and on how much you pay to execute them. Here’s how prices are quoted, why spreads exist, which fees apply, and how to compute your all-in cost to make professional decisions.
What Bid and Ask Mean (and how they’re used)
Every instrument shows two prices:
- Bid: the price at which the market buys from you if you sell now.
- Ask: the price at which the market sells to you if you buy now.
Example: EUR/USD shows Bid 1.1000 and Ask 1.1002. If you buy, you’re filled at 1.1002; if you sell, you’re filled at 1.1000.
The mid price (1.1001) is a reference only—not an executable price.
What the Spread Is and Why It Exists
The spread is the difference between Ask and Bid. It compensates liquidity providers for quoting firm prices in real time and taking inventory risk.
Spreads react to:
- Liquidity (more participants = tighter spreads).
- Volatility (surprises/news = wider spreads).
- Session (London/NY overlap compresses spreads; Asia often widens them).
- Broker model (ECN/STP = tighter spreads + commission; market maker may offer fixed spreads with cost “embedded”).
Spread types and their impact
- Fixed spread: predictable; can still widen in extreme events.
- Variable spread: adjusts to liquidity; usually tight in active hours and wider in thin markets.
Focus on your effective average spread for your symbols and hours, not only the marketing “from”.
Commissions, swaps and other fees
Beyond spread, consider:
- Commission per trade: common on ECN/STP; charged per side or round-turn.
- Swap / overnight financing: debit/credit for holding positions overnight.
- Exchange/clearing fees (equities/futures) and possible FX conversion.
- Slippage: difference between expected and filled price (can be positive or negative).
How to compute your all-in cost (practical examples)
All-in cost = Spread in cash + Commissions ± Slippage ± Swap (if held overnight).
Forex example (EUR/USD, 1 standard lot = 100k):
- Pip value ≈ $10.
- Spread 1.2 pips → $12.
- ECN commission $7 round-turn → total $19 if in/out with no slippage.
You need ~1.9 pips in your favor to break even.
Index example (CFD US500):
- Spread 0.8 points, commission $0 → cost = 0.8 × value/point.
- Add 0.2 points slippage on entry → total 1.0 point cost.
Equities example (cash or CFD):
- Commission per share or percentage + possible exchange fee.
- In thin stocks, spread and slippage can dominate total cost.
Strategy and costs: scalping, day trading, swing
- Scalping: needs tight spreads, low commissions and minimal slippage; ECN + high-liquidity hours help.
- Day trading: still cost-sensitive but intraday swings can absorb fees; avoid news if your setups suffer from spread spikes.
- Swing: relative cost per trade is smaller vs. target size, but swap/rollover matters (mind weekly triple swap on some brokers).
Best practices to reduce costs
- Trade during liquid hours (major opens and overlaps).
- Avoid market orders right on news unless your system is built for it.
- Consider limit orders for price improvement (maker/taker fee models may reward makers).
- Optimize position sizing and avoid excessive micro-trades.
- Track your average slippage and effective spread; pick the routing/model that fits your style.
Operational recap
Read bid/ask, translate spread + commission + slippage into cash, and compute your break-even. With that clarity, you’ll choose better symbols, hours, broker, and order types, bringing more consistency to your trading plan.
