Forwards and Futures - Instrument Basics › Futures Contracts
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Futures contracts evolved to address the limitations of forwards while preserving their economic purpose. A futures contract is a standardized agreement to buy or sell an asset at a specified future date, but unlike forwards, futures trade on organized exchanges with standardized terms and centralized clearing.
An exchange-traded, standardized contract obligating the buyer to purchase and the seller to deliver a specified quantity of an underlying asset at a predetermined price on a future date. Futures are marked to market daily with gains and losses settled through margin accounts.
The standardization of futures contracts covers several key dimensions:
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Contract size: Each contract specifies a fixed quantity of the underlying. For example, one crude oil futures contract on the CME represents 1,000 barrels.
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Delivery date: Contracts mature on specific dates, typically identified by month and year (e.g., "December 2024 corn futures").
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Delivery specifications: For physically delivered contracts, the exchange specifies acceptable grades of the commodity, delivery locations, and delivery procedures.
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Tick size: The minimum price increment varies by contract; for example, crude oil futures might trade in increments of $0.01 per barrel
This standardization creates fungibility: one December 2024 corn futures contract is identical to any other, enabling buyers and sellers to trade anonymously on an exchange without negotiating terms.
The Role of the Clearinghouse
The critical innovation that distinguishes futures from forwards is the clearinghouse. When two parties trade a futures contract on an exchange, the clearinghouse interposes itself between them, becoming the buyer to every seller and the seller to every buyer. This process, called novation, eliminates bilateral counterparty risk; instead of worrying about whether your specific counterparty will honor the contract, you only need to trust the clearinghouse.
Clearinghouses manage their risk through several mechanisms:
- Margin requirements: Both buyers and sellers must post collateral.
- Daily settlement: Gains and losses are settled each day rather than accumulating until maturity.
- Position limits: Maximum contract holdings prevent excessive concentration of risk.
- Default procedures: If a clearing member defaults, the clearinghouse has resources to cover losses.
Major futures clearinghouses continued to function and settle contracts during the 1987 stock market crash, the 2008 financial crisis, and the market volatility of 2020.
Margin and Marking to Market
The margin system is central to futures mechanics and represents an effective solution to counterparty risk in financial markets. Rather than allowing potential losses to accumulate over the life of a contract (as happens with forwards), the futures market settles gains and losses daily, so neither party ever owes the other an amount materially larger than the collateral on deposit.
When you open a futures position, you don't pay the full contract value; instead, you deposit initial margin, a good-faith deposit typically representing 5-15% of the contract's notional value. This deposit is a performance bond, showing your financial capacity to honor the contract and providing a buffer against potential losses.
The minimum amount of funds you must deposit with your broker to open a futures position. Initial margin represents a security deposit against potential losses, not a down payment on the underlying asset.
Initial margin and a down payment have different economic functions. When you buy a house with a 10% down payment, you are purchasing equity in the property and financing the remainder. When you post 10% initial margin on a futures contract, you are not buying any portion of the underlying asset. Instead, you are posting collateral that can be seized if you fail to honor your contractual obligations. The full economic exposure to the underlying asset belongs to you from day one, but ownership of the asset itself never transfers until delivery (if physical settlement occurs).
Each trading day, the exchange settles all contracts at the official settlement price (typically based on trading activity near the close). The change in contract value from the previous day is immediately credited to or debited from your margin account, a process called marking to market. This daily settlement mechanism turns what would be a single large payment at maturity into a series of smaller daily payments, dramatically reducing credit exposure between counterparties.
Consider going long one crude oil futures contract (1,000 barrels) at $75 per barrel. The following code simulates the daily marking-to-market process, tracking the margin balance as settlement prices change:
import pandas as pd
# Crude oil futures example
contract_size = 1000 # barrels per contract
entry_price = 75.00 # dollars per barrel
initial_margin = 6000 # typical initial margin for crude oil
maintenance_margin = 4500 # maintenance margin level
# Simulated daily settlement prices
settlement_prices = [75.00, 76.20, 74.80, 73.50, 72.00, 74.50, 76.00]
# Calculate daily P&L and margin account balance
data = []
margin_balance = initial_margin
for day, price in enumerate(settlement_prices):
if day == 0:
daily_pnl = 0
cumulative_pnl = 0
else:
daily_pnl = (price - settlement_prices[day - 1]) * contract_size
cumulative_pnl = (price - entry_price) * contract_size
margin_balance += daily_pnl
margin_call = (
max(0, initial_margin - margin_balance)
if margin_balance < maintenance_margin
else 0
)
margin_balance += margin_call
data.append(
{
"Day": day,
"Settlement Price": price,
"Daily P&L": daily_pnl,
"Cumulative P&L": cumulative_pnl,
"Margin Balance": margin_balance,
"Margin Call": margin_call,
}
)
margin_df = pd.DataFrame(data)Daily Marking-to-Market for Long Crude Oil Futures Position =========================================================================== Contract size: 1,000 barrels Entry price: $75.00/barrel Initial margin: $6,000 Maintenance margin: $4,500 Day Settlement Price Daily P&L Cumulative P&L Margin Balance Margin Call 0 75.00 0.00 0.00 6,000.00 0.00 1 76.20 1,200.00 1,200.00 7,200.00 0.00 2 74.80 -1,400.00 -200.00 5,800.00 0.00 3 73.50 -1,300.00 -1,500.00 4,500.00 0.00 4 72.00 -1,500.00 -3,000.00 6,000.00 3,000.00 5 74.50 2,500.00 -500.00 8,500.00 0.00 6 76.00 1,500.00 1,000.00 10,000.00 0.00
The simulation shows the marking-to-market process. On Day 1, prices rise from $75.00 to $76.20, generating a profit of $1,200 (1,000 barrels × $1.20). This amount is immediately credited to the margin account, which now stands at $7,200. You have 'realized' this gain even though the position remains open. On Day 2, prices fall to $74.80, and the loss of $1,400 is immediately debited from the account. The margin balance drops to $5,800 still above the maintenance threshold. The situation becomes more critical as prices continue to decline. By Day 4, with prices at $72.00, the cumulative loss of $3,000 has reduced the margin account to $3,000, which falls below the maintenance margin threshold of $4,500. This breach triggers a margin call.
A demand from the broker for you to deposit additional funds when the margin account balance falls below the maintenance margin. Failure to meet a margin call results in forced liquidation of your position.
The margin call mechanism is designed to ensure that losing positions are either adequately collateralized or closed before losses can exceed the available margin. When a margin call occurs, you must deposit enough funds to restore the account to the initial margin level. Restoring the account only to the maintenance margin is insufficient. The higher initial margin level provides a cushion for continued price movements and reduces the frequency of margin calls.
You must understand how initial margin, maintenance margin, and margin calls relate. The gap between these two levels provides a buffer that absorbs normal daily price fluctuations without triggering margin calls. Only when cumulative losses eat through this buffer does a margin call occur. The size of this buffer reflects the exchange's assessment of typical daily price volatility for the contract.
The daily settlement mechanism means that futures P&L is realized incrementally rather than all at expiration. This has practical implications for financing: if you have a winning position, you receive cash daily and can earn interest on it, while a losing position requires ongoing funding. This timing difference between futures (daily settlement) and forwards (settlement at maturity) creates subtle but important pricing differences between the two instruments, particularly when interest rates are volatile or correlated with the underlying asset price.
Key Parameters
The key parameters for the margin calculation are:
- Initial Margin: The collateral required to open the position ($6,000). This amount is set by the exchange based on the contract's volatility and represents the expected maximum one-day loss at a high confidence level. Higher volatility contracts require larger initial margins.
- Maintenance Margin: The minimum balance required to keep the position open ($4,500). Typically set at 70-80% of initial margin, this threshold triggers margin calls when breached. The gap between initial and maintenance margin provides a buffer for normal daily fluctuations.
- Settlement Price: The daily closing price used to mark the position to market. This price is determined by the exchange based on trading activity near the close and is the official valuation for margin calculations.
- Contract size: The amount of the underlying asset per contract (1,000 barrels). This multiplier converts price changes per unit into dollar gains and losses per contract.
Settlement and Delivery
Most futures contracts offer two settlement methods:
Physical delivery requires the short position holder to deliver the actual underlying asset to the long position holder at a designated delivery point. For agricultural commodities, this might mean delivering grain to an approved warehouse. For crude oil, it means arranging pipeline delivery to Cushing, Oklahoma (for WTI futures). Physical delivery ensures that futures prices converge to spot prices at expiration; if they didn't, arbitrageurs would exploit the difference.
Cash settlement avoids the logistics of physical delivery. At expiration, the contract is marked to market against the final settlement price (often based on an index or reference rate), and the cash difference is exchanged. Stock index futures, for example, settle in cash because delivering a basket of 500 stocks would be impractical.
In practice, very few futures contracts result in physical delivery. Most traders close their positions before expiration by entering an offsetting trade. If you are long one December crude oil futures contract, you can exit by selling one December crude oil futures contract; the two positions net to zero.