Bid-Ask Spread

IntermediateStock Market2 min read

Quick Definition

The difference between the highest price a buyer will pay (bid) and the lowest price a seller will accept (ask) for a security.

What Is Bid-Ask Spread?

The Bid-Ask Spread is the difference between the bid price (what buyers are willing to pay) and the ask price (what sellers are willing to accept). This spread represents a transaction cost for investors and a profit opportunity for market makers.

The Two Prices:

  • Bid Price: The highest price a buyer is currently willing to pay
  • Ask Price: The lowest price a seller is currently willing to accept
  • Spread: Ask Price - Bid Price

Example:

StockBidAskSpreadSpread %
Large-Cap (AAPL)$150.00$150.02$0.020.01%
Mid-Cap$45.00$45.10$0.100.22%
Small-Cap$8.00$8.25$0.253.13%
Penny Stock$0.50$0.60$0.1020%

Factors Affecting Spread:

  1. Liquidity: More trading volume = tighter spreads
  2. Volatility: Higher volatility = wider spreads
  3. Market Hours: Spreads widen after hours
  4. Stock Price: Lower-priced stocks often have wider percentage spreads
  5. Market Conditions: Spreads widen during market stress

Why Spreads Matter:

  • Immediate cost when buying and selling
  • Affects day trading profitability
  • Indicates market liquidity
  • Wider spreads signal higher risk

Trading Implications:

  • Use limit orders in wide-spread stocks
  • Avoid frequent trading in illiquid securities
  • Consider spread when calculating breakeven