What it means
Exchanges match orders, but they do not settle them. The clearing corporation takes over at that point, replacing the original contract with two new ones through a process called novation, so that it sits in the middle of every position.
The reason this matters is counterparty risk, the danger that the person on the other side of your trade cannot pay. Without a central guarantor, every institution would have to assess the creditworthiness of every other institution it dealt with, which would make markets far slower and far more expensive.
Margin is the main tool. Members post initial margin when a position is opened, an estimate of the worst plausible loss over a day or two, and then pay or receive variation margin each day as prices move.
Behind margin sits the default waterfall, an agreed order in which losses are absorbed if a member fails. The defaulting member's own margin goes first, then its default fund contribution, then a slice of the clearing corporation's own capital, and only then the pooled contributions of the surviving members.
The nuance worth recognising is concentration. Because so much risk now sits inside a handful of clearing corporations, regulators treat them as systemically important and set detailed rules on their capital, stress testing and recovery planning.
In practice
Real-world examples.
Example
A commodities broker fails after a sharp move in natural gas prices. The clearing corporation seizes the firm's posted margin, auctions its open positions to other members over two days, and every client on the other side of those trades is paid in full without knowing anything went wrong.
Example
A pension fund moves its interest rate swaps from bilateral agreements with three banks into a central clearing corporation. It posts more collateral than before, but it no longer has to negotiate credit terms with each bank individually and can close a position with any member rather than only the original counterparty.
Example
A grain merchant hedges next season's harvest with 400 futures contracts. Because the clearing corporation guarantees settlement, the merchant's bank is willing to treat the hedge as genuine risk reduction and lends against the crop at a lower rate.
Formula
Calculation
Variation margin = (today's settlement price - yesterday's settlement price) x contract size x number of contracts
Margin call = required initial margin - current account balance
A trader is long 10 crude oil futures contracts, each covering 1,000 barrels. The clearing corporation requires initial margin of $6,000 per contract, so 10 x $6,000 = $60,000 sits in the account, with a maintenance level of $5,000 per contract, or 10 x $5,000 = $50,000.
The settlement price falls from $80.00 to $78.50 a barrel. Variation margin is ($78.50 - $80.00) x 1,000 x 10 = -$15,000, which the clearing corporation collects overnight and pays to the members on the other side of those positions.
The account balance drops to $60,000 - $15,000 = $45,000. That is below the $50,000 maintenance level, so the trader receives a margin call to restore the full initial requirement: $60,000 - $45,000 = $15,000 to be wired the same morning or the position is closed out by the clearing member.Case study
Seen in the real world.
The following is an illustrative and entirely fictional example. Harbourgate Clearing, an invented clearing corporation for regional energy futures, held $840,000,000 of member margin and a $210,000,000 default fund contributed by its 42 members. Its rules said that a defaulting member's margin was used first, then that member's own $5,000,000 default fund share, then $30,000,000 of Harbourgate's own capital, and only then the pooled fund.
A mid-sized member, Fenwold Trading, built a concentrated position on the assumption that gas prices would stay in a narrow band. When prices moved 22% in three sessions, Fenwold could not meet a $64,000,000 variation margin call and was declared in default before the market opened.
Harbourgate applied Fenwold's $58,000,000 of posted margin, then its $5,000,000 default fund share, and auctioned the remaining positions to four other members at a further loss of $9,000,000. The shortfall of $64,000,000 + $9,000,000 - $58,000,000 - $5,000,000 = $10,000,000 was absorbed entirely by Harbourgate's own $30,000,000 capital layer, so no surviving member lost a cent and, in this fictional scenario, the wider market never noticed.
Watch out
Common mistakes.
- Confusing the exchange with the clearing corporation, when the first matches trades and the second guarantees and settles them.
- Assuming central clearing removes risk rather than concentrating and managing it, which is why default funds and stress tests exist.
- Treating margin as a cost or a fee, when it is collateral that is returned when the position is closed.
Questions
People also ask.
Do individual investors deal with a clearing corporation directly?
No, they deal with a broker, and only the broker or its clearing agent is a member of the clearing corporation.
What is the difference between clearing and settlement?
Clearing works out who owes what and guarantees performance, while settlement is the actual exchange of cash and securities that follows.
Can a clearing corporation itself fail?
It is possible but deliberately made very unlikely, since it is required to hold capital, run a layered default waterfall and maintain a written recovery plan.
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