How Do Stock Prices Move?
1. Price is an agreement
A stock price is the latest price at which a buyer and seller agreed to exchange shares.
The exchange does not invent the price. The company does not update it every second. The price emerges
from orders placed by market participants.
Every completed trade records an agreement. The next trade may happen at the same price, a higher price
or a lower price.
2. Buyers create bids
A bid is the price a buyer is willing to pay. Different buyers may place bids at different prices and quantities.
A buyer usually wants the lowest possible price, but may raise the bid when competing demand is strong.
3. Sellers create offers
An offer, also called an ask, is the price at which a seller is willing to sell.
A seller usually wants the highest possible price, but may lower the offer when selling urgency increases.
4. Bid, ask and spread
The highest available bid and the lowest available ask form the immediate trading range.
The difference between them is called the bid-ask spread.
Liquid stocks usually have narrow spreads because many participants compete. Illiquid stocks may have
wide spreads, making entry and exit more expensive.
5. A simple order-book example
Suppose the best buyer is willing to pay Rs 499 and the best seller is willing to accept Rs 501. The spread is
Rs 2.
A trade occurs only when a buyer accepts Rs 501, a seller accepts Rs 499, or a new order is placed at an
agreed price.
If aggressive buyers repeatedly accept higher offers, the traded price rises. If aggressive sellers repeatedly
hit lower bids, the price falls.
6. Demand and supply in the market
Demand means the willingness and ability to buy shares at various prices. Supply means the willingness
and ability to sell shares.
Price rises when available selling supply is insufficient to satisfy aggressive buying demand at the current
price.
Price falls when available buying demand is insufficient to absorb aggressive selling supply.
7. Price discovery
Price discovery is the continuous process through which the market finds a price acceptable to buyers and
sellers.
It incorporates public information, expectations, fear, greed, liquidity needs, portfolio decisions and different
time horizons.
Because expectations change, price discovery never truly stops while the market is open.
8. Why expectations matter more than headlines
Markets react not only to whether news is good or bad, but to whether it is better or worse than expected.
A company may report profit growth and still fall if investors expected much stronger growth. Another
company may report weak results and rise if the outcome was less bad than feared.
Price reflects the difference between reality and expectations.
9. The role of institutional orders
Large mutual funds, insurers, foreign institutions and proprietary desks can trade quantities far larger than
most individuals.
A large order may be divided and executed over time to reduce market impact.
Persistent institutional demand can create sustained price and volume strength. Persistent institutional
selling can create prolonged weakness.
10. Liquidity changes how easily price moves
In a highly liquid stock, a large number of buy and sell orders may absorb normal transactions without major
price movement.
In an illiquid stock, even a modest order can move the price sharply because fewer shares are available
near the current price.
This is why percentage movement alone does not reveal the quality or tradability of a stock.
11. Market orders and limit orders
A market order seeks immediate execution at the best available price. It prioritises speed, not the exact
price.
A limit order specifies the maximum price a buyer will pay or the minimum price a seller will accept.
In fast or illiquid markets, market orders can execute at worse prices than expected. This difference is called
slippage.
12. Gaps
A gap occurs when a stock opens significantly above or below the previous closing price because overnight
demand or supply has shifted.
News, global markets, results or large orders can create gaps.
A stop loss does not guarantee execution at the exact stop price when a stock gaps through that level.
13. Why price can move without obvious news
Not all market decisions are publicly explained in real time.
Funds rebalance portfolios, traders cover short positions, investors need cash, index weights change and
large participants alter risk exposure.
The chart records the result of these decisions even when the reason is unknown.
14. Common beginner mistakes
- Assuming every rise is caused by good news
- Price may rise because expectations changed, sellers disappeared or large buyers accumulated.
- Assuming a falling stock must be cheap
- A lower price can reflect deteriorating demand or new information.
- Ignoring liquidity
- A quoted price is useful only if you can transact a reasonable quantity near it.
- Chasing an already extended move
- Aggressive buying after a sharp rise can produce poor risk-reward.
- Believing the last traded price guarantees your execution
- Your order may execute differently depending on spread, depth and speed.
15. DStreet principle
Price is the final record of the struggle between demand and supply. Respect what price is doing before
explaining why it should do something else.
16. Beginner checklist
- A stock price is the latest agreed transaction price.
- Bids come from buyers; offers come from sellers.
- The bid-ask spread is a real trading cost.
- Aggressive demand can push price upward.
- Aggressive supply can push price downward.
- Expectations influence reactions to news.
- A stop order cannot eliminate gap risk.
- Liquidity affects slippage and price movement.
17. Quick knowledge check
Question: Who decides a stock's market price?
Answer: Buyers and sellers through their orders and completed trades.
Question: What is a bid?
Answer: The price a buyer is willing to pay.
Question: What is an ask or offer?
Answer: The price a seller is willing to accept.
Question: What is the spread?
Answer: The difference between the best bid and best ask.
Question: Why can good news cause a price decline?
Answer: Because the result may be worse than market expectations.
18. Next lesson
What Are NSE and BSE? The next article explains where Indian equity trading happens and what an
exchange actually does.