Spread widening
Family VII · Market & styles
Not to be confused with spread, forex spread, spread betting forex.
Spread widening refers to an expansion of the bid-ask spread, the gap between the highest price a buyer will pay and the lowest price a seller will accept. It commonly occurs when market liquidity falls or volatility rises, as market makers demand greater compensation for risk. The effect is a higher immediate cost for entering or exiting a position.
Causes and context
Widening is driven by changes in supply and demand for liquidity. During normal conditions, spreads are narrow because many participants compete to quote prices. When uncertainty increases—such as around economic data releases, central bank announcements, or geopolitical events—market makers may widen quotes or withdraw entirely. Spreads also widen outside major trading hours, when fewer participants are active. The degree of widening varies by instrument, venue, and broker.
Worked example
Assume a stock normally trades with a bid of 50.00 and an ask of 50.02, a spread of 0.02. A news release causes the ask to rise to 50.10 while the bid remains 50.00.
The spread has widened by 0.08, or 400% of its original width. A trader buying at the ask and immediately selling at the bid would incur a cost of 0.10 per share instead of 0.02.
Practical implications
Wider spreads increase transaction costs, reduce the effectiveness of short-term strategies, and can trigger stop-loss orders more easily because the bid or ask may move sharply. Traders often avoid entering positions during known widening periods or use limit orders to control execution price. The exact spread at any moment depends on the specific market and broker.
Often confused with
- spread
- Spread is the general difference between bid and ask, while spread widening is the specific increase in that difference; the visible sign is a change in the quoted gap over time.
- forex spread
- Forex spread is the bid-ask difference in currency pairs, whereas spread widening is the expansion of that difference; the visible sign is a larger pip value for the same pair.
- spread betting forex
- Spread betting forex is a derivative product where the spread is the cost of placing a bet, not the underlying market spread; the visible sign is that the quoted spread is set by the provider and may not reflect interbank rates.