How the Bid-Ask Spread Affects Your Trades
The bid-ask spread is the difference between the highest price a buyer will pay (bid) and the lowest price a seller will accept (ask). Every time you enter a trade, you pay this spread as a hidden cost. If a stock has a bid of $50.00 and an ask of $50.05, you start each round-trip trade down $0.05 before the price even moves.
How the Spread Works as a Trading Cost
When you buy with a market order, you pay the ask price. When you sell, you receive the bid price. That gap is the spread, and it goes straight to the market maker providing liquidity.
For a single trade, the cost seems tiny. But multiply it across your trading volume. If you day trade 20 round trips per day on a stock with a $0.05 spread, that is $1.00 per day in spread costs alone, or $250 per year. On wider spreads or larger position sizes, this number grows fast.
Why Spreads Widen
Spreads are not fixed. They fluctuate based on conditions. During high volatility events like earnings announcements, Fed meetings, or economic data releases, market makers widen spreads to protect themselves from rapid price changes.
Low-volume instruments naturally have wider spreads. A thinly traded small-cap stock might have a $0.10 or $0.20 spread, while the S&P 500 futures contract (ES) typically trades with a one-tick ($0.25) spread. Time of day matters too: spreads tend to be tightest during regular trading hours when volume is highest.
How to Minimize Spread Costs
Choose liquid instruments. Major indices, large-cap stocks, and popular forex pairs have the tightest spreads. The more actively traded the instrument, the lower your spread cost.
Use limit orders. Instead of crossing the spread with a market order, place a limit order at the bid (for buys) or ask (for sells). You provide liquidity instead of taking it, potentially getting filled at a better price.
Trade during peak hours. US market hours of 9:30 AM to 4:00 PM Eastern offer the tightest spreads for stocks and futures. For forex, the London-New York overlap provides peak liquidity.
Factor spreads into your strategy. If your average winning trade is only $0.10, a $0.05 spread eats half your profit. Scalping strategies require ultra-tight spreads to be viable.
Key Takeaways
- The bid-ask spread is a hidden cost on every trade you make
- Wider spreads during volatility and off-hours increase your trading costs
- Liquid instruments like ES futures and major forex pairs have the tightest spreads
- Limit orders help you avoid paying the full spread
- Always factor spread costs into your strategy’s expected profitability
Frequently Asked Questions
Is the spread the same as a commission? No. Commissions are fees charged by your broker. The spread is a market-driven cost built into the price difference between buyers and sellers. You pay both on every trade.
Can I see the spread on my trading platform? Yes. Most platforms display the bid and ask prices. The DOM (Depth of Market) view shows the full order book with prices and sizes on both sides.
Do prop firms have different spreads? Prop firms route orders through various liquidity providers, which can result in slightly different spreads than retail brokers. Compare execution quality during your evaluation to understand the true cost.
Risk Disclaimer: Trading involves substantial risk of loss. Past performance is not indicative of future results. See our full risk disclaimer.