How Much Capital Do You Need to Trade Commodities? Margin, Lot Size & Premium

Suppose you want exposure to ₹10 lakh worth of Gold. If you were buying ₹10 lakh worth of Gold in the physical market, you would ordinarily have to pay roughly ₹10 lakh to own it.

Commodity derivatives work differently.

With a futures contract, you generally do not pay the entire value represented by the contract upfront. Instead, a smaller amount is maintained against the position as margin.

With an option, the capital requirement changes again. An option buyer pays a premium, while an option seller receives that premium but generally has to maintain margin against the position.

So two trades linked to the same commodity can require very different amounts of capital.

That gives us two numbers to keep separate throughout this chapter: the capital required to take the position and the market exposure that position creates. They are not necessarily the same thing.

We introduced lot size in Chapter 7 as the minimum quantity you trade through a commodity contract. Here, it starts affecting the money involved.

Suppose one lot of a futures contract represents 100 units of a commodity and the futures price is ₹5,000 per unit.

The value represented by that one contract is: ₹5,000 × 100 = ₹5,00,000

That ₹5 lakh is the contract value.

So, in a simple case where the price and lot size are expressed in the same unit: Contract Value = Futures Price × Lot Size

This is why the quoted price alone does not tell you how large a commodity trade is. A contract quoted at ₹5,000 could represent 10 units, 100 units or considerably more. The quantity represented by one lot changes the exposure.

Note: Some commodities are quoted for a specific quantity rather than per single unit. For example, Gold may be quoted per 10 grams while the contract represents a larger quantity. In such cases, the quoted price has to be adjusted to match the full lot before calculating the contract value.

The same commodity may also be available through different contract variants. Depending on what the exchange lists, you may find standard, mini or smaller-denomination contracts.

A smaller contract represents a smaller quantity of the same commodity. That means one lot creates less exposure and will generally require less capital as well.

Now suppose our ₹5 lakh futures contract requires ₹50,000 in margin.

Margin is the amount of money that must be maintained against a futures position. It is generally only a fraction of the full contract value, and the amount can differ across contracts or change with market conditions.

In this example:

• Contract Value = ₹5,00,000
• Illustrative Margin Required = ₹50,000

You are not buying ₹50,000 worth of the contract. You are taking the full ₹5 lakh futures position while ₹50,000 is maintained against it.

That difference creates leverage.

The contract value tells you how much market exposure the position represents. The margin tells you how much capital is required against it.

If the futures price moves, however, your gain or loss is still calculated on the full contract quantity, not on the margin blocked.

Lot size also tells you what a movement on the screen means in rupees. Suppose one contract represents 100 units and the futures price moves by ₹10.

Across the entire contract: ₹10 × 100 = ₹1,000

The quoted price moved by ₹10, but the value of the position changed by ₹1,000.

Each exchange-traded contract also has a tick size, which is the smallest permitted movement in its quoted price.

If the tick size is ₹0.50 and the contract represents 100 units:

₹0.50 × 100 = ₹50

A one-tick move therefore changes the position by ₹50.

So even a small movement on the chart has to be read together with the quantity represented by the contract.

Futures gains and losses are settled daily through mark-to-market, or MTM.

Suppose you buy a futures contract at ₹5,000 and one lot represents 100 units.

If the futures price falls to ₹4,990:

₹10 × 100 = ₹1,000 loss

That ₹1,000 loss is reflected through the daily settlement process while the position remains open.

This matters because the gain or loss is based on the full contract quantity, not merely on the amount originally blocked as margin.

If losses reduce the funds available in the account, additional capital may be required to continue maintaining the position.

The capital calculation changes when you take the view through an option.

An option buyer pays a premium, and that premium has to be read together with the lot size.

Suppose a commodity Call Option trades at a premium of ₹50 per unit and one lot represents 100 units.

The total premium outlay is: ₹50 × 100 = ₹5,000

So: Total Premium Outlay = Premium × Lot Size

A premium of ₹50 does not mean buying one lot costs ₹50. In this example, the option buyer pays ₹5,000.

This can make the upfront capital requirement very different from a futures position. A futures trader maintains margin against the futures position, while an option buyer pays the premium required for the option position.

The two may begin with the same view on the commodity, but their risk and payoff are different.

While the position remains a long option, the buyer's maximum loss is the premium paid. If the option later results in a futures position under the applicable contract rules, that resulting position has its own margin and exposure.

A low premium does not automatically mean a low-risk or attractive trade. The lot size determines the actual amount paid, and the buyer can still lose the entire premium.

The position looks very different from the seller's side. An option seller receives the premium, but also takes on the obligation attached to the option. Because of that obligation, selling an option generally requires margin.

So if an option seller receives ₹5,000 in premium, that does not mean ₹5,000 is the only number that matters. The seller may need substantially more capital available to support the position.

The exact margin depends on the position and the applicable margin framework rather than a single percentage or formula that works for every option sale.

We now have three different capital structures:

• Futures → Margin required against the futures position
• Option Buyer → Premium × Lot Size paid
• Option Seller → Premium received, but margin also required

We can now come back to the question we started with.

If a futures contract represents ₹5 lakh of a commodity, you may need only a fraction of that amount as margin to take the position. But your P&L still responds to the full contract quantity.

If you buy an option, your upfront outlay comes from the premium multiplied by the lot size.

If you sell an option, you receive premium but generally have to maintain margin against the position.

So knowing whether you have enough money to enter a trade is only one part of understanding it.

The other question is how much exposure that capital creates and how the position can behave when the market moves.

Whether that exposure is appropriate for the size of your account is a risk-management question, which we will deal with properly in Chapter 12.

For now, the distinction to carry forward is simpler:

The next question is what makes the price of the commodity itself move. That takes us to Chapter 9: What Moves Commodity Prices?

• Lot size tells you how much of a commodity one contract represents and therefore affects the value and exposure of the position.
• Contract value measures the market exposure represented by a futures contract, while margin is the capital required against that position.
• Margin creates leverage, so futures P&L is based on the full contract quantity even when the capital blocked is much smaller than the contract value.
• For an option buyer, premium × lot size determines the total premium outlay. An option seller receives premium but generally has to maintain margin.
• The amount of capital required to take a position and the market exposure created by that position are not necessarily the same thing.