Margin

A trade is agreed on one day and settled on another. In between, the exchange is exposed to a simple question: what if one side does not turn up?

Margin is the answer. Both buyers and sellers of equity are required to pay a percentage of their dues upfront, at the time of placing the order. If they then default, that deposit absorbs the loss, and the settlement completes for everybody else.

It is a deposit, not a payment. The margin is not part of the price; it sits with the clearing corporation as collateral and is released when the obligation is met.

Two collection points, not one. Brokers collect margins from the clients when the order is placed. Stock exchanges collect margins from the brokers when the order is executed. Those are different events and different parties, and the exam separates them.

In the cash market the margin is a percentage of the trade value, set by the exchange. The workbook's worked rate is 17%.

In derivatives the structure is layered:

• Initial margin is charged to the trading account on the assumption that the position will be carried until expiry. It has two components — SPAN margin and ELM (extreme loss margin) based on exposure — and both must be deposited before the trade is taken.
• The initial margin is sized to be large enough to cover the loss in 99 per cent of cases. The greater the volatility of the stock, the greater the risk, and therefore the greater the initial margin.
• Premium margin is charged, in addition, to trading members trading in option contracts. It is paid by the buyers of options and equals the options premium multiplied by the quantity purchased.

Margin sits inside a wider risk-management frame: base minimum capital deposited by members against which no exposure is allowed, additional capital adequate to cover all margin payments, and index-based market-wide circuit breakers at 10%, 15% and 20%.

Cash market, the workbook's own case. An investor buys 100 shares of Company X at Rs 100 on 1 January 2020 and must pay in Rs 10,000 by 3 January 2020. Two risks live in those two days: the buyer may not bring the funds, and the seller may not deliver the shares.

Margin at 17%  =  10,000 x 17%  =  Rs 1,700 paid in advance

Scale it to a real order. 2,000 shares at Rs 640 = Rs 12,80,000, and at the same 17% the client must have Rs 2,17,600 with the broker before the order goes in — even though nothing is owed for two more days.

Derivatives. The same client buys 10 lots of a stock option, lot size 50, at a premium of Rs 84.

Premium margin = 84 x (10 x 50) = 84 x 500 = Rs 42,000

That is the entire outlay for the option buyer, and it is his maximum loss. The writer of those same options is in a different position altogether: he receives the Rs 42,000 premium but must post initial margin = SPAN + ELM before the trade, and that requirement rises as the stock gets more volatile.

The asymmetry is the examinable point. Buying an option costs a premium. Writing one costs a margin that the exchange can raise on you mid-position.

Chapter 6 (Securities Market Segments) sets margin inside the risk-management machinery of the secondary market, alongside base minimum capital and circuit breakers — that is where the 17% illustration lives. Chapter 10 (Understanding Derivatives) gives the margining process: initial margin, SPAN and ELM, and premium margin. Expect questions on who collects margin from whom and when, on which components make up initial margin, and on the direction of the relationship between volatility and margin.

• Broker collects from client at order placement; exchange collects from broker at execution. Two different moments. Questions swap them.
• Initial margin is SPAN plus ELM, and both are mandatory before the trade — not one or the other, and not after the position is taken.
• Premium margin is additional to initial margin and applies to option contracts. It is the premium times the quantity, and it is the option buyer's cost.
• Higher volatility means higher initial margin. If your reasoning produces a lower margin for a riskier stock, it is inverted.
• 99 per cent is a confidence level, not a guarantee. One day in a hundred, by design, the initial margin is not enough — which is why ELM and the wider risk framework exist.
• Margins are payable by both parties to a futures contract. Only the option buyer escapes initial margin, because his loss is capped at the premium he has already paid.
• Margin is collateral, not consideration. Paying Rs 1,700 of margin does not reduce the Rs 10,000 that must be paid in on settlement day.