Bid-Ask Spread is the heart of trading: offers and bids explained clearly

Why Do You Need to Understand Bid and Offer Before Trading?

When you open a trading app, you’ll see two numbers constantly changing — the Bid price (buying price) and the Offer price (selling price). These pairs of numbers are not random; they result from the actual buying and selling decisions of millions of investors worldwide. Understanding this mechanism is the difference between professional traders and beginners.

Bid Is the Price Buyers Are Truly Willing to Pay

Bid refers to the highest price that a securities buyer is willing to pay at the moment. This number reflects market demand — the more buyers there are, the higher the Bid price will be because they compete to acquire what they want.

When you are a securities seller, you will receive the price at the highest Bid in the market at that time. This is why today’s Bid price is often lower than the Offer — buyers tend to bid lower initially to negotiate with sellers.

Offer Is the Price Sellers Truly Want

Offer is the minimum price that sellers are willing to accept for their securities. If you want to buy any stock or asset now, you must pay the Offer price. This price indicates the (supply) of assets that sellers are ready to deliver.

Offers are used in almost every financial market — from common stocks, bonds, options, to foreign exchange. The number of Offers indicates whether there are sellers in the market.

The Spread (Spread) Between Bid and Offer Is the Hidden Cost

The difference between the Bid and Offer prices is called the spread. For example, if the Bid is 100 Baht and the Offer is 101 Baht, the spread is 1 Baht. This spread is the money that the intermediary (broker) or the market keeps for facilitating trades.

Narrow spread indicates high liquidity — assets are traded very frequently, e.g., large-cap stocks. A wide spread suggests low liquidity — assets like startup stocks or certain bonds are traded less often.

Understanding this is crucial because when you buy and sell assets, the amount you lose to the spread is an unnecessary cost that could be avoided with better decision-making.

Demand and Supply Drive Bid and Offer

Bid and Offer prices are not static. When demand (buyers) exceeds supply (sellers), both Bid and Offer will rise together because buyers are willing to pay more to acquire assets.

Conversely, when supply exceeds demand, Bid and Offer prices decrease as sellers lower their prices to attract buyers. This demand-supply mechanism occurs every second in the market, making Bid and Offer real-time indicators of market conditions.

How to Read and Interpret Bid-Offer Situations

When analyzing Bid-Offer, observe these four patterns:

Case 1: Narrow Bid and Narrow Offer — The market has a trend but low volume; trading is minimal or just starting. Watch closely; as volume increases, it may present trading opportunities.

Case 2: Narrow Bid and Wide Offer — A strong signal: buyers are continuously entering, but sellers are few. This is a tough environment for large investors, as they may push the Offer higher and higher.

Case 3: Wide Bid and Narrow Offer — Usually occurs at the end of a trend; if buying continues but Bid-Offer remains, it might be better to pass. Prices often stay relatively stable during this phase.

Case 4: Wide Bid and Wide Offer — Volume is at its peak. If this occurs at the start of a trend or at a level sufficient to break through resistance, prices could surge. But if at the end of a trend, it’s best to avoid.

Comparing Details: Bid vs. Offer

Real-Life Example: Why Do Profits Disappear?

Phromchai is a retail investor wanting to buy Stock A. He looks at the screen and sees the current price at $173. He decides to buy 10 shares, expecting to pay $1,730.

However, the actual cost turns out to be $1,731. Phromchai is confused — why? Later, he finds out that the $173 shown is the last traded price, but his order was filled at the current Offer of $173.10. That’s the actual price he paid. Others placed buy orders at $172.90 (Bid), but Phromchai saw the average at $173 and got confused.

This case illustrates how the spread (difference of $0.20) affects profit and loss.

Benefits and Limitations of Bid-Offer

Benefits:

• Helps make quick entry and exit decisions
• Indicates market liquidity
• Provides insight into market sentiment (more or fewer buyers)
• Aids in smarter limit and stop-loss orders

Limitations:

• Wide spreads increase hidden costs
• Beginners may be “trapped” into buying at expensive Offer prices
• Cannot predict true value, as market conditions change every second
• On normal days, low volume widens the Bid-Offer spread, making transactions more difficult

Offer and Bid with Different Types of Orders

Market order — Accepts the current Offer (if buying) or Bid (if selling) immediately, without choice.

Limit order — Sets a desired price; the order waits until the market matches your Bid or Offer.

Stop loss — Sets a fixed exit point; during volatile markets, you might have to accept a Bid lower than your set level.

Summary: Not as Difficult as You Think

Bid and Offer are not just numbers for professional traders but fundamental market mechanisms. Those who understand Bid-Offer and spreads can:

• Better time their entry and exit
• Assess market liquidity
• Avoid unnecessary costs from unwise trades
• Understand why their profits are less than expected

Whether you’re a long-term investor or a short-term trader, understanding the Bid-Offer system is a foundational skill. Learning this will help ensure your investment decisions yield better returns.