NISM Series XVI – Commodity Derivatives: Chapter 6 – Trading Mechanisms (Short Notes)

This is Part 6 of 7 in our complete NISM Series XVI Commodity Derivatives short notes series. In this chapter, we cover the structure and functioning of commodity derivatives exchanges in India — types of members, trading systems, order types, trading parameters, contract specifications, and participants. These are highly practical topics that feature prominently in the NISM XVI exam.

Not read the earlier parts yet? Start with Part 1: Introduction to Commodity Markets.

1. Membership on Commodity Derivatives Exchanges

Membership of commodity derivatives exchanges in India is governed by the SEBI Stock Brokers Regulations. SEBI prescribes the procedures for grant of recognition, types of members, net worth criteria, deposit requirements, and fees for each category of member.

Categories of Members:

Member Type	Abbreviation	Key Rights and Functions
Trading Member	TM	Can execute trades on their own account AND on behalf of registered clients. Cannot clear and settle trades independently — requires a clearing member for settlement.
Self-Clearing Member / Trading cum Clearing Member	SCM / TCM	Can execute trades on their own account and for clients, AND can also clear and settle those trades themselves. Also carries out risk management and trade confirmation through the trading system.
Professional Clearing Member	PCM	Entitled to clear and settle trades executed by other members (TMs and TCMs) but does NOT have the right to execute trades directly.
Authorized Persons	APs	Part of the broker's network to expand reach; act on behalf of the broker to service clients. SEBI permitted the Authorized Person network to expand brokers' distribution.

2. Trading System in Commodity Derivatives Exchanges A. Screen-Based Trading System (SBTS)

Commodity derivatives exchanges in India use a nationwide online fully automated screen-based trading system (SBTS). Key features:

Trading members enter buy and sell orders with their desired prices through the electronic system.
The system matches orders automatically — a trade is executed as soon as a buy order matches a sell order.
Order matching follows price-time priority: the best price is matched first, and among orders at the same price, the one entered earliest gets priority.
All trades are transparent — prices are publicly visible to all market participants.

B. Algorithmic Trading (Algo Trading)

Algorithmic trading refers to using computer programs to automatically generate and execute orders in the market with minimal or no human intervention, based on pre-defined parameters.

Key characteristics of algo trading:

A computer algorithm automatically determines order parameters such as initiation, timing, price, and quantity.
Algo trading does not require human intervention at the time of order placement.
Uses mathematical models and pre-set instructions for timing, price, and quantity.
Allows placement of orders at faster pace and higher frequency than manual trading.
Any order generated using automated execution logic is classified as an algorithmic trade.

3. Trading Hours

Trading on commodity exchanges takes place on all working days except Saturdays, Sundays, and exchange-notified holidays. Holidays are notified by the exchange in advance.

Note: Commodity exchanges in India often have extended trading hours compared to equity markets, allowing for international price alignment (especially for metals and energy).

4. Important Trading Parameters

Parameter	Description
Base Price	When a new futures contract is first made available for trading, the exchange sets a base price, which is used to determine the Daily Price Limit (DPL) on the first day of trading.
Circuit Filter / Daily Price Range (DPR) / Daily Price Limit (DPL)	The maximum price range within which a contract can be traded during a single trading day. If a trade would breach this limit, it is not executed. Prevents extreme intraday price swings.
Daily Settlement Price	Used to calculate the daily mark-to-market (MTM) profit or loss on open futures positions at the end of each trading day.
Final Settlement Price	The price used for the "delivery default penalty" in cases of non-delivery when a short seller fails to deliver the commodity.
Delivery Logic	Pre-specified in contract specifications. It defines the options available to buyers and sellers regarding delivery during the tender/delivery period (compulsory, both options, or seller's option).
Tick Size	The minimum price movement allowed for a commodity futures contract. Differs from commodity to commodity.
Tick Value	The monetary profit or loss per contract for a one-tick price change. Formula: Tick Value = (Lot Size ÷ Quotation Factor) × Tick Size

All commodity exchanges continuously display open price, low price, high price, and last traded price on a real-time basis on their trading screens throughout the trading session.

5. Contract Specifications for Commodity Derivatives

Every commodity futures or options contract listed on an exchange has a detailed contract specification document. Key elements include:

Contract start date and contract expiry date
Trading unit and lot size
Maximum order size
Tick size (minimum price movement)
Daily price limit (circuit filter)
Initial margin, additional/special margin (if any)
Maximum permissible open positions (client-level and member-level)
Delivery centres
Delivery logic
Due date
Quality specifications for the commodity
Last day of trading
Tender period, tender period margin
Delivery period, delivery margin
Funds pay-in and pay-out schedule
Delivery pay-in and pay-out schedule
Delivery default penalty provisions

6. Order Types and Conditions A. Price-Related Orders

Order Type	Description
Limit Order	The buyer or seller specifies the price at which the trade should execute. For a buyer, the limit price is typically below the current asking price; for a seller, it is above the current bid price. The order executes only at the specified price or better.
Market Order	Executed immediately at the best available current market price at the time of placement. No price is specified — the order fills at whatever price the market offers.
Stop Loss Order	Placed after entering a trade to limit potential losses if prices move in an unfavourable direction. Automatically triggers a market or limit order when the stop price is reached.
Trailing Stop Loss Order	A dynamic stop loss order where the stop price adjusts automatically based on the settings defined at initiation. Designed to both minimize losses and protect profits as the position moves in favour.

B. Time-Related Orders

Order Type	Description
Day Order	Must be executed on the same trading day it is entered. If not executed by end of day, the exchange automatically cancels it.
Good-Till-Date (GTD) Order	Remains active until a specific date chosen by the trader. Automatically cancelled if not executed by that date.
Good-Till-Cancelled (GTC) Order	Remains active in the system until either it is executed or the trader manually cancels it. No automatic expiry.
Immediate or Cancel (IOC) Order	Requires all or part of the order to be executed immediately. Any portion not immediately filled is automatically cancelled. No waiting in the order book.

Modification and Cancellation of Orders:

Members are permitted to modify or cancel orders before they are executed. Important rule: Time priority does not change when an order is modified due to a decrease in quantity or a decrease in disclosed quantity — the original time position in the queue is preserved.

7. Tracking Commodity Futures and Options Prices

The Market Watch window on the trading system enables investors and members to view real-time market details for any listed contract. It displays:

Instrument type and symbol
Price quotation unit
Buy price and sell price
Last Traded Price (LTP)
Average traded price
Buy quantity and sell quantity
Contract value
Daily low price and daily high price
Previous close price
Expiry date
Option type (call/put)
Open interest
Volume traded
Percentage change and net change (in ₹) from previous close

8. Participants in Commodity Derivatives Markets

SEBI has identified the following categories of participants who are permitted to trade in commodity derivatives markets in India:

Farmers and Farmer Producing Organisations (FPOs)
Processors (e.g., flour mills, oil refineries)
Eligible Foreign Entities (EFEs — foreign participants with actual commodity exposure allowed to hedge)
Margin Traders (participants who trade using margin without physical commodity exposure)
Arbitrageurs and Traders
Institutional Players (Mutual funds, Portfolio Management Services — PMS)

Quick Revision – Key Exam Points

Orders are matched on a price-time priority basis in exchange trading systems.
The SBTS (Screen-Based Trading System) is a fully automated, nationwide online trading platform.
A PCM (Professional Clearing Member) can clear but CANNOT execute trades.
A TM (Trading Member) can execute but CANNOT independently clear trades.
A TCM / SCM can both execute AND clear trades.
Daily Price Limit (DPL) = Circuit filter = Daily Price Range (DPR) — these are the same thing.
Daily settlement price = Used for MTM calculation.
Final settlement price = Used for delivery default penalty.
Time priority does NOT change when order quantity is decreased (but does change when price is changed).
Commodity trading hours exclude Saturdays, Sundays, and exchange-notified holidays.

Practice Questions (NISM XVI Pattern)

What is the basis for order matching in commodity derivatives exchanges?
Answer: Price-time priority — best price first; among same-priced orders, earliest entered gets priority.
A Professional Clearing Member (PCM) wants to execute their own proprietary trades on the exchange. Are they allowed to do this?
Answer: No. A PCM can only clear and settle trades; they do not have the right to execute trades.
What does "tick value" represent?
Answer: The monetary profit or loss per contract for a one-tick (minimum price movement) change in the futures price. Formula: (Lot Size ÷ Quotation Factor) × Tick Size
Which order remains active in the system indefinitely until manually cancelled?
Answer: Good-Till-Cancelled (GTC) order
What is an IOC (Immediate or Cancel) order?
Answer: An order that must be executed immediately (all or part); any unfilled portion is instantly cancelled.
When a member modifies an order by reducing its quantity, does the time priority of that order change?
Answer: No — time priority is preserved when quantity is decreased.

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