Demand คือ ความต้องการซื้อ - เข้าใจระบบราคาหุ้นและสูตรเทรดสำเร็จ

If you are an investor and have wondered, “Why do stock prices go up and down?” or “Why are buying and selling pressures important for making profits?” the answer lies in the fundamental concept called Demand and Supply, which is central to market analysis from both economic theory and practical trading perspectives. Demand is the desire to buy securities at various price levels. Understanding this concept will open the door for you to see market movements more clearly.

Demand: What It Is and How It Drives Market Prices

Demand is a basic idea reflecting the quantity of goods or services that buyers are willing to pay for at different prices. When investors observe stock prices moving upward, it’s often because buyers are eager to purchase that stock — that’s actual demand in action.

The fundamental law of demand states that there is an inverse relationship between demand and price — as price rises, demand decreases; as price falls, demand increases. This phenomenon occurs due to two effects:

Income Effect: When prices drop, your purchasing power increases. You can buy more than usual.

Substitution Effect: When the price of a product decreases, it becomes relatively cheaper than substitute goods, prompting buyers to choose this product over others.

Successful traders often observe demand by watching price movements. When prices hit new lows, buying interest may return strongly — indicating clear demand.

Supply: The Selling Pressure — Balancing Buyers and Sellers

If we define demand as the quantity buyers want to purchase, then supply is the quantity sellers are willing to offer at various prices. When many sellers are waiting to sell at a certain price level, that’s supply or selling pressure.

The law of supply is opposite to demand — as prices increase, sellers are more willing to sell; as prices decrease, they are less willing. Factors influencing supply in financial markets include:

• Company policies, such as share buybacks reducing available shares or issuing new shares increasing supply
• New listings (IPOs) introducing fresh securities
• Regulations and legal restrictions affecting issuance
• Sellers’ ability to find liquidity

Price Equilibrium: Where Demand Meets Supply

Actual market prices are not determined by demand alone or supply alone but at the intersection where demand and supply curves meet — called the equilibrium point.

When prices rise above equilibrium, excess supply (more goods than buyers want) occurs, prompting sellers to lower prices until balance is restored. Conversely, if prices fall below equilibrium, excess demand (more buyers than available goods) drives prices upward.

This equilibrium point is not fixed; it shifts when external factors such as news, economic policies, or events influence market sentiment.

Factors Driving Demand and Supply in Financial Markets

Financial markets are more complex than basic commodity markets because many factors influence demand and supply:

• Major demand drivers:

  • Low interest rates incentivize investors to seek higher returns in stocks
  • Abundant money supply increases investors’ purchasing power
  • Growing confidence in future economic prospects
  • Strong corporate earnings

• Supply factors:

  • Expansion of company production capacity
  • Entry of new competitors
  • Changes in economic policies

Effective investors do not just watch prices but also analyze how these factors will influence future demand and supply.

Applying Demand and Supply in Fundamental Analysis

Fundamental analysts view stock prices as representations of a company’s value (market cap), not just market numbers. When positive earnings forecasts emerge, the demand to own a share of that good company increases — that’s demand in action.

Conversely, bad news pushes sellers to lower prices, reducing supply and confidence, leading to decreased demand.

Smart investors try to anticipate how these factors will shift demand and supply in the near future, rather than just reacting to current prices.

Technical Analysis Tools for Reading Demand and Supply

Price Action Analysis:

• Green candlesticks (close higher than open) indicate demand (buying pressure) winning.
• Red candlesticks (close lower than open) indicate supply (selling pressure) dominating.
• Doji candles (open equals close) suggest indecision or balance.

Trend Recognition:

• Continuous upward price movement signals strong demand.
• Continuous downward movement indicates dominant supply.
• Sideways or choppy prices suggest equilibrium.

Support & Resistance:

• Resistance levels are where demand weakens and supply increases.
• Support levels are where supply diminishes and demand strengthens.

Demand and Supply Zones: Professional Trading Strategies

Demand and supply zones identify points where price loses and regains balance, offering trading opportunities.

Example 1: DBR (Drop Base Rally) — Reversal Upward

• Excess supply causes rapid price drops.
• Demand responds, creating a base.
• Good news triggers demand dominance, breaking resistance and continuing upward — traders enter on breakout.

Example 2: RBR (Rally Base Rally) — Continued Uptrend

• Excess demand causes quick price rises.
• Supply reacts, forming a base.
• When demand resumes strength, price breaks resistance and continues upward.

Traders use these zones to time entries, capturing clear directional moves during transition phases.

Why Investors Must Understand Demand and Supply

Grasping demand and supply bridges the gap between economic theory and real trading practice. When you see prices rising, you’re not just observing numbers changing — you’re witnessing real-time battles between buyers and sellers.

Demand is the core of market activity. Learning to read, infer, and anticipate shifts in demand and supply makes trading less about guesswork and more about informed decision-making.