Spot vs. Futures: The Basics of Expiration and Margin

Financial Literacy · Futures Investing 101

Investing Basics: Understanding the Fundamentals of Futures

Investing Basics: Understanding the Fundamentals of Futures — featured image

You’ve probably seen headlines like “futures selling drove the market down” or “leveraged trader gets liquidated.” But if someone asked you “what exactly is a futures contract?”, it’s not an easy question to answer on the spot. In this article, we’ll walk through what futures are and how they’re actually traded — starting with terms like expiration, margin, and leverage, and building up to why that scary word “liquidation” comes up in the first place.

LIST
01What Is a Futures Contract?Starting with how it differs from spot trading 02Expiration and Contract UnitsExpiration, near/far-month contracts, rollover, multiplier 03Margin and LeverageInitial/maintenance margin, leverage ratio, long/short 04How Are Futures Actually Traded?Opening/closing positions, account setup, worked example 05Why Do Futures Prices Differ from Spot Prices?The concept and logic of basis 06Contango (When Futures Prices Are Higher)The logic behind the normal state 07Backwardation (When Futures Prices Are Lower)The logic behind the exceptional state 08How Does a Margin Call Happen?Falling below maintenance margin and requests for more funds 09What Happens When You Get Liquidated?Forced offsetting trades and how excess losses are handled 10Why Do We Even Need Futures?Two purposes: hedging and speculation 11Risks Every Beginner Should KnowLeverage, expiration, unlimited losses 12SUMMARYKey terms and checklist recap
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SECTION 01

What Is a Futures Contract?

1The comparison point: spot trading happens right now

To understand futures, it helps to start with the spot trading we’re already familiar with. If you buy Samsung Electronics stock today, the shares land in your account today, and you pay for them today. It works exactly like buying something at a convenience store — you pay, and you get the item immediately. The “stock price” we check every day is this spot price.

2Futures are a promise to trade at a set price in the future

What is a futures contract
A futures contract is an agreement, made today, to buy or sell something at a specific future date for a price set right now. Nothing actually changes hands today — only the promise does. The key point is that this promise is an obligation: once you enter the contract, you have to follow through with it.
A simple analogy
Imagine a cabbage farmer and the owner of a kimchi factory. The farmer worries cabbage prices might crash by harvest season, while the factory owner worries prices might spike by then. So the two of them make a deal today: “Three months from now, we’ll trade one head of cabbage for 3,000 won.” That way, the farmer is protected even if prices fall — he still gets 3,000 won — and the factory owner is protected even if prices rise, since he can still buy at 3,000 won. That’s the basic logic behind a futures contract. Stock market futures work the same way: it’s a promise made today to buy or sell the KOSPI200 index at a set price three months from now.

🇰🇷 Korea

KOSPI200 futures, Korean Treasury bond futures, and similar products trade on the Korea Exchange (KRX).

🇺🇸 United States

S&P 500 futures (E-mini S&P 500), crude oil futures (WTI), and similar products trade on exchanges like the CME (Chicago Mercantile Exchange).

3So what actually trades as spot, and what trades as futures?

Individual stocks like Samsung Electronics are usually traded as spot. When you tap the “buy” button on a brokerage app, that’s a spot transaction. The three categories below, on the other hand, are the ones where futures trading is especially active.

Asset class with active futures trading Examples
Indices Indices made up of multiple stocks, such as KOSPI200 or the S&P 500
Commodities Physical goods such as crude oil (WTI), gold, or agricultural products
Currencies Exchange rates themselves, such as the USD/KRW rate

For reference, individual stocks like Samsung Electronics can technically be traded as futures too — the Korea Exchange offers “single-stock futures.” But trading volume there is far lower than for index futures, so in practice, when people say “futures,” they usually mean the index, commodity, and currency futures listed in the table above.

SECTION 02

Expiration and Contract Units

1Expiration date

The expiration date is the future date by which the contract must be settled. KOSPI200 futures expire on the second Thursday of March, June, September, and December. Here’s an interesting detail: at any given moment, contracts with several different expiration dates are trading simultaneously. The contract with the nearest expiration is called the near-month contract, and the next one out is the far-month contract. For example, if it’s currently July, the September contract (near-month) and the December contract (far-month) are both trading at the same time. Most of the trading volume is concentrated in the near-month contract.

What if expiration is approaching but you want to keep your position?
That’s where rollover comes in. It means closing out your current near-month contract before it expires, and opening a new position in the next contract — the far-month one. For example, if you’re holding a September contract and expiration is approaching, you’d close out the September position and open a new buy (or sell) in the December contract. Rollover is a normal part of keeping a position running continuously, but as we’ll see in Section 6, if the market is in contango, you have to keep switching into progressively more expensive far-month contracts — which can quietly rack up a bit of cost over time.

2Contract unit (multiplier)

Futures aren’t traded “per share” the way individual stocks are — they’re traded in fixed contract units. For KOSPI200 futures, each index point is multiplied by ₩250,000.

Contract value = index level × multiplier (₩250,000)
Contract value at an index level of 1,120
₩280,000,000
Roughly in line with the KOSPI200 index level as of July 2026

Trading just one contract already means controlling an asset worth over ₩280 million. Understanding the multiplier is what lets you grasp exactly how large a trade you’re actually making.

One thing to watch out for
₩250,000 is specific to KOSPI200 futures. Contract units are set completely differently for each futures product, so don’t assume “it’s probably ₩250,000” when you’re looking at some other product.
Futures product Contract unit
KOSPI200 futures ₩250,000 per index point
Crude oil futures (WTI) 1 contract = 1,000 barrels of crude oil
Gold futures 1 contract = 100 troy ounces of gold
USD currency futures 1 contract = $10,000

The way “how much is one contract worth” is calculated is completely different depending on the asset type. Index futures use “index level × multiplier,” commodity futures use “price × physical quantity,” and currency futures use “exchange rate × notional amount.” That’s why, whenever you encounter a new futures product, it’s worth making a habit of checking its contract unit first.

SECTION 03

Margin and Leverage

1Margin (initial margin and maintenance margin)

With futures, you don’t pay the full contract value up front — you can trade by depositing just a portion of it as collateral. This money is called margin, and there are two types.

Type Meaning
Initial margin The amount you must deposit to open a position (roughly 10% of the contract value)
Maintenance margin The minimum balance that must stay in your account to keep the position open (usually about 70–80% of the initial margin)

Trouble starts when your account balance falls below the maintenance margin — we’ll cover exactly what happens then in Section 8.

2Leverage

Leverage refers to the effect of controlling a much larger contract value using only a small amount of margin.

Leverage ratio = contract value ÷ margin
₩280,000,000 ÷ ₩28,000,000
10x leverage

In other words, it’s the same effect as controlling an asset worth 10 times your own money — so even a small price move produces a much larger gain or loss relative to your margin.

3Long positions and short positions

Long position
A “buy” contract, taken when you expect the price to go up.
Short position
A “sell” contract, taken when you expect the price to go down.

With spot stocks, “short selling” requires borrowing shares first and involves a fairly cumbersome process. A short position in futures is different — there’s no such procedure. It’s simply executed with a single sell order.

SECTION 04

How Are Futures Actually Traded?

1Opening and closing a position

Futures trading starts by placing an order to open a long or short position. At any point, you can place an opposite order (a sell if you’re long, a buy if you’re short) to close the position and lock in your gain or loss. You’re not required to hold a position all the way to expiration — in fact, most individual investors close their positions well before that point.

2If you want to trade in Korea

For individuals trading futures in Korea, the requirements below must be met. Because it’s a high-leverage, high-risk product, these rules exist to confirm at least a baseline level of understanding.

Opening a derivatives account — this must be a separate account from a regular stock trading account.
Completing prior education — you must take and complete a mandatory training course.
Minimum deposit — you must deposit a set minimum amount in advance.

3Getting a feel for it with a worked example

Let’s continue with the KOSPI200 futures example from before (index level 1,120, multiplier ₩250,000, margin ₩28,000,000).

Item Amount
Contract value 1,120 × ₩250,000 = ₩280,000,000
Required margin (approx. 10%) Approx. ₩28,000,000
Change in contract value if the index rises 5% +Approx. ₩14,000,000
Return relative to margin Approx. +50%
You put in just ₩28,000,000, and a 5% move in the index produces close to a 50% gain (or loss). That’s the leverage effect in action.
SECTION 05

Why Do Futures Prices Differ from Spot Prices?

1The concept of basis

Oddly enough, even though it’s the same underlying asset, the spot price and the futures price are always slightly different. This gap is called the basis.

Basis = futures price − spot price
KOSPI200 (expiring in 3 months)
Spot 1,120 Futures 1,124

In this example, the basis is 1,124 − 1,120 = +4 points.

2Why does this gap exist?

The futures price bakes in “the cost of holding the asset until expiration.” If you imagine buying the stock now and holding it until expiration, you’d pay interest costs over that period, but you’d also collect dividends. This net cost of carry (interest cost minus dividends, and similar factors) is what gets added onto the futures price.

Futures price ≈ spot price + interest cost − expected dividend yield

We’ll walk through exactly how this formula plays out as contango and backwardation, with real numbers, in the next section.

SECTION 06

Contango (When Futures Prices Are Higher)

Contango and backwardation are just names for which direction the basis (futures price − spot price) is tilted. Let’s start with contango, which is the more common state.

1The normal state, where the futures price is higher

Under normal conditions, interest cost outweighs expected dividend yield. So in the formula “futures price ≈ spot price + interest cost − expected dividend yield,” the interest cost term dominates, and the futures price ends up higher than the spot price. This everyday state — where interest cost exceeds dividend yield — is called contango.

2Working through the numbers

Say the annual interest rate is 3% and the KOSPI200’s expected dividend yield is 1.5% — a gap of 1.5% per year. With 3 months (one quarter of a year) left until expiration, we divide that gap by 4, giving 1,120 × 1.5% ÷ 4 ≈ 4.2 points added to the futures price.

Contango example
Spot 1,120 Futures 1,124

🇰🇷 Korea: KOSPI200 futures are frequently in contango, largely driven by the gap between dividend yield and interest rates.

SECTION 07

Backwardation (When Futures Prices Are Lower)

Backwardation is the opposite of contango — an exceptional state where the futures price ends up lower than the spot price. Let’s look at why this reversal happens, first for stocks and indices, then for commodities.

1For stocks and indices

Things flip when dividend season approaches — periods like April or December, when many companies pay out dividends. Say the expected dividend yield suddenly jumps to 4.5%. The gap with the 3% interest rate becomes −1.5% annually, and over a 3-month horizon that works out to 1,120 × (−1.5%) ÷ 4 ≈ −4.2 points. In other words, the stronger the expectation of “a solid dividend payout coming soon,” the more the futures price drops below the spot price to reflect it.

Dividend-season example
Spot 1,120 Futures 1,116

2For commodities

Commodities like crude oil or gold don’t pay dividends, but they have something else: demand for “having the physical good right now” — what’s known as a convenience yield. For instance, if a war or supply disruption creates a sudden oil shortage, refiners will want oil “in hand today” far more than oil “delivered in the future.” As a result, spot oil trades at a premium, and the spot price ends up higher than the futures price — that’s backwardation. WTI crude oil futures are a classic example, frequently slipping into backwardation due to storage constraints or geopolitical issues.

3They meet in the end, at expiration

As expiration approaches, the futures price converges toward the spot price, and by the expiration date they end up equal — the basis converges to zero.

This connects directly back to the rollover concept from Section 2 (switching into the next expiration’s contract). Rolling over during contango means switching into a more expensive far-month contract each time, which quietly erodes value (often called “roll cost” or “contango loss”). Rolling over during backwardation, on the other hand, actually works in your favor — you switch into a cheaper far-month contract.

🇺🇸 United States: Crude oil futures (WTI) are a well-known example of a product that frequently slips into backwardation, due to storage costs and supply issues.

SECTION 08

How Does a Margin Call Happen?

1When you fall below the maintenance margin

This is where the maintenance margin from Section 3 becomes critical. Problems begin the moment your losses grow large enough to push your account balance below the maintenance margin level. Let’s continue the earlier example with concrete numbers.

Item Amount
Initial margin (paid when opening the position) ₩28,000,000
Maintenance margin (approx. 80% of initial margin) Approx. ₩22,400,000
Loss if the index drops 5% ₩14,000,000
Account balance after the loss ₩28,000,000 − ₩14,000,000 = ₩14,000,000

The account balance of ₩14,000,000 is now below the maintenance margin level of ₩22,400,000. This is exactly the moment a margin call is triggered.

2Margin calls: a request for more funds

When margin runs short like this, your broker will ask you to “top up the shortfall” — this is called a margin call. Brokers typically require you to bring the balance back up not just to the maintenance margin, but all the way to the original initial margin level. In the example above, you’d need to deposit an additional ₩14,000,000 to bring the balance from ₩14,000,000 back up to ₩28,000,000.

So exactly when is the deadline?
It varies slightly by broker, but most require the deposit by noon on the next trading day after the margin call is triggered. For example, if a margin call happens after Monday’s market close, you’d typically need to deposit the shortfall by noon on Tuesday. This deadline is set out in each broker’s terms and conditions, so it’s worth checking your specific broker’s policy before you start trading.
SECTION 09

What Happens When You Get Liquidated?

1Liquidation (forced offsetting trade)

If you can’t top up your margin by the deadline, your broker will forcibly close out your position. This is exactly what’s meant when you see news or forum posts about someone “getting liquidated trading futures.” Whether you’re long or short, any position where you’ve taken on an obligation and posted margin is equally exposed to this risk.

Margin call issued, deadline missed
Broker executes an offsetting order at the current market price
Position forcibly closed (liquidation)

Because this happens urgently at market price, if the market is crashing (or spiking) at that moment, you could end up liquidated at a worse price than expected — which can make the loss even larger.

2What if your account is still negative after liquidation?

This is the part that worries people most. Sometimes losses grow so large that liquidation still doesn’t fully cover them — your margin alone isn’t enough. For example, if the index crashes 15% in a single day and your loss balloons to ₩42,000,000, you’d lose the entire ₩28,000,000 initial margin and still be short ₩14,000,000.

Collateral and debt don’t behave the same way
This shortfall behaves a little differently from the “margin is collateral, not a loan” principle explained earlier. You never borrowed that money to begin with, but once you’ve entered into a contract obligating you to trade, you’re on the hook for the full loss — and any amount beyond your margin becomes a debt you owe your broker. The broker will demand immediate repayment; if you don’t pay in time, you can be charged late fees, it can hurt your credit standing, and in serious cases it can even lead to legal action.
Futures don’t work on a “you can only lose what you put in” basis. You can lose more than you put in, and that excess is a real debt you have to pay back.
SECTION 10

Why Do We Even Need Futures?

So far, we’ve covered what futures are, how they’re traded, and the risks involved. So why would anyone bother trading something this complicated and potentially risky? There are broadly two reasons. One is hedging — trying to eliminate price-movement risk ahead of time. The other is speculation — trying to profit from price movement itself. Let’s look at each.

Hedging (risk avoidance)
Just like the cabbage farmer example earlier, this is used to eliminate future price-movement risk in advance. Companies often use futures to protect against a spike in commodity prices, or exporters use them to reduce exposure to currency-rate swings.
Speculation (profit-seeking)
Futures are also used to bet on price direction, aiming for a large payoff from a relatively small amount of capital. Just remember: the leverage effect magnifies gains just as much as it magnifies losses.
SECTION 11

Risks Every Beginner Should Know

Leverage cuts both ways — controlling a large contract with a small amount of money means gains and losses are both magnified by the same multiple. Jumping in just because “you can start with a small amount” is a risky mindset.
Don’t forget about expiration and rollover — as we saw in Section 2, futures have a fixed expiration date, so keeping a position open requires rolling over before expiration. And as we saw in Section 6, if the market is in contango, each rollover quietly adds up a bit of cost — an easy detail to overlook.
Unlimited losses on short positions — a short futures position has, in theory, no cap on potential losses. If the price keeps rising against you, your losses can keep growing indefinitely — a critical thing to remember.
SUMMARY

Key Terms and Checklist Recap

Term One-line summary
SpotA real transaction where you buy now and receive it now
FuturesAn “obligation” contract to buy or sell at a set price at a future date
Near-month / far-month contractThe contract with the nearest expiration / the next one out
MultiplierThe factor used to convert one index point into contract value (₩250,000 for KOSPI200 futures)
Initial / maintenance marginThe amount paid to open a position / the minimum balance required to keep it open
LeverageThe effect of controlling a large amount with a small amount of money
Margin callA request to add more margin when losses grow too large
Liquidation (offsetting trade)A forced closing of a position when a margin call isn’t met
BasisThe gap between the futures price and the spot price
Contango / backwardationA state where the futures price is higher / lower than the spot price
RolloverSwitching from an expiring contract into the next expiration’s contract
Expiration, contract units, margin, and leverage — we confirmed these using a KOSPI200 futures example.
The difference between spot and futures — we confirmed the fundamental distinction: an obligation versus an immediate transaction.
Basis, contango, and backwardation — we confirmed with real numbers why and how futures and spot prices diverge.
Margin calls and liquidation — we confirmed how they happen, how they play out, and how any excess loss is handled.
Expiration/rollover and unlimited losses on short positions — we recapped the risks beginners tend to overlook.
Futures let you control a large contract with a small amount of margin — which means you need a solid grasp of leverage, margin calls, and liquidation before you can approach them safely.
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CONCLUSION

Wrapping Up

Futures come up constantly in the news, but at their core they start from a simple idea: a promise about the future. It’s the machinery built on top of that idea — margin, leverage, margin calls, liquidation — that can make things feel complicated for beginners.

To recap the essentials: futures let you control a large contract with a relatively small margin, which magnifies both gains and losses; if you fail to top up your margin within the deadline, your position can be forcibly liquidated; and if the resulting loss exceeds your margin, that excess becomes a real debt you have to repay.

If you keep in mind that “you can lose more than you put in,” you’ll be much better equipped to approach futures safely. In the next installment, we’ll move on to the basics of options, a product that’s often discussed alongside futures.

This article is based on the KOSPI200 index and Korea’s domestic futures trading system as of July 2026. Last updated: July 2026.

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