What Happens When You Buy a Stock?
1. Step 1: You create an order
You choose the security, exchange, quantity, order type and price conditions.
The broker validates the instruction against available funds, product rules, market status and risk controls.
2. Step 2: The broker routes the order
If the order passes validation, the broker sends it to the selected exchange.
The order receives identifiers and enters the exchange order book according to its price and time priority.
3. Step 3: The exchange searches for a match
A buy order can execute only against compatible sell orders.
A marketable order may match immediately. A limit order may remain pending if no seller accepts its price.
4. Order vs trade
An order is your instruction. A trade is the completed match between a buyer and seller.
One order can create multiple trades at different prices if the required quantity is filled from several sellers.
5. Partial execution
Suppose you place an order for 1,000 shares, but only 300 are available at your acceptable price.
The first 300 may execute while the remaining 700 stay pending, get cancelled or execute later depending on the order conditions and market.
6. Average traded price
When parts of an order execute at different prices, the platform calculates a weighted average execution price.
The last traded price displayed on the screen is not necessarily your average price.
7. Trade confirmation
After execution, the broker displays the trade and later provides formal records such as a contract note.
Notifications and exchange messages help confirm that activity occurred in your account.
8. Clearing
The clearing system determines what each broker and participant must deliver: funds from the buyer side and securities from the seller side.
It also applies risk-management processes designed to reduce counterparty failure.
9. Settlement
Settlement completes the transfer of funds and securities according to the applicable cycle.
The exact market cycle can change under regulation, so the principle is more important than memorising a fixed label: execution happens first, settlement follows.
11. Why an order may be rejected
Insufficient available funds
Invalid price or quantity conditions
Security not permitted for the selected product
Market or security restrictions
Exchange price bands or surveillance controls
Account, segment or KYC restrictions
Broker risk-management limits
12. Why an order may stay pending
Your limit price is not accepted by sellers
The stock is illiquid
Your quantity is large relative to available supply
The market is closed or in a different session
The stock has reached an applicable circuit limit
13. Cancelling or modifying
A pending order can usually be modified or cancelled while the exchange permits it.
Already executed quantity cannot be cancelled. Only the remaining unexecuted part can be changed.
14. Charges and net cost
The economic cost is not only quantity multiplied by price.
Applicable brokerage, exchange charges, taxes, duties and other levies affect the final debit. The contract note shows the detailed calculation.
15. Common beginner mistakes
- Thinking order placement means purchase
- A pending order is not a trade.
- Looking only at last traded price
- Execution depends on available sellers and order conditions.
- Ignoring partial fills
- The executed quantity may be smaller than the order quantity.
- Treating unsettled shares as fully available
- Settlement status affects delivery and withdrawal processes.
16. DStreet principle
Know the state of every instruction: placed, pending, partially filled, completed, rejected or cancelled.
17. Beginner checklist
- I verify the security and exchange.
- I verify quantity, order type and price.
- I check actual executed quantity.
- I review average price and charges.
- I confirm the contract note and Demat credit.
18. Quick knowledge check
Question: What is the difference between an order and a trade?
Answer: An order is an instruction; a trade is an executed match.
Question: Can one order execute in several trades?
Answer: Yes.
Question: Why might a limit order remain pending?
Answer: No seller accepted the specified price.
Question: When is ownership fully settled?
Answer: After the applicable settlement process and Demat credit.
19. Next lesson
Delivery, Intraday and Margin.