Imagine walking into a jewellery shop to buy a gold coin. The shopkeeper sells it to you for ₹50,000. Two minutes later, you change your mind and ask the shopkeeper to buy it back. The shopkeeper agrees, but offers you only ₹48,000. You have just lost ₹2,000 without the market price of gold changing at all. This difference is the cost of transaction. In the stock market, a very similar transaction cost exists. It is called the bid-ask spread, and it is the most common hidden fee that retail investors pay without realizing it.

The Two Prices of Every Stock

When you look at a stock quote on your trading terminal, you see a single price. This is usually the price of the last traded share. But in reality, every stock has two prices at any given millisecond: the Bid and the Ask.

• The Bid is the maximum price that buyers are willing to pay for the stock.
• The Ask (or Offer) is the minimum price that sellers are willing to accept for the stock.

The Ask is always higher than the Bid. The difference between these two prices is the bid-ask spread. When you place a market order to buy, you buy at the higher Ask price. When you place a market order to sell, you sell at the lower Bid price.

The Cost of Illiquidity in Small-Caps

For large, popular companies, millions of shares are traded every day. Because there are so many buyers and sellers competing, the bid-ask spread is extremely small—often just a few paise. We call these stocks highly liquid.

However, small-cap companies or thinly traded stocks are illiquid. Very few people are trading them. To get a transaction done quickly in these stocks, you have to accept a much wider gap between the buying and selling price. This gap acts as an immediate penalty the moment you enter and exit the trade.

You can easily protect yourself from this hidden cost on stock-analyze.com by checking the liquidity rating and average bid-ask spread on any stock's detailed analysis page before you buy.