What is a settlement price used for?

Marking every open position to market, calculating margin calls, determining whether options are exercised, and settling expiring contracts in cash. One number, published once a day, drives payments across the entire market.

How is this different from banging the close?

Banging the close is the term used for aggressive trading in a closing settlement window, particularly in commodities. Settlement price manipulation is the broader category, covering any official settlement including those derived from other markets or from submitted quotes.

Why is the window so short?

Because a settlement must be timely and objective. Longer windows are harder to manipulate but slower to publish and less representative of the closing state of the market. Venues trade off these considerations explicitly.

What is trade at settlement?

A mechanism allowing participants to agree now to trade at whatever the settlement turns out to be. It lets those who need the settlement price obtain it without trading in the window, which reduces legitimate window volume and makes remaining aggression more conspicuous.

Do clearing houses have a role?

Yes, and a direct one. They calculate margin from settlement prices, so a manipulated settlement forces genuine participants to post cash or liquidate. The clearing house is the transmission mechanism through which the harm reaches everyone else.

Is a volume-weighted settlement safer than a last price?

Substantially. A settlement derived from the volume-weighted average of a window requires far more capital to move than one derived from the last trade. Most venues have moved in this direction for exactly this reason.

What must a regulator prove?

Under the traditional claim, an artificial price and intent to create it. Under Rule 180.1, deception. Under the disruptive practices provision, intentional or reckless disregard for orderly execution during the closing period, which is the least demanding of the three.

Can exchanges act on their own?

Yes, and they do. Adjusting settlement methodology, lengthening windows, imposing position limits into expiry, and disciplining participants under their own rulebooks are all available without waiting for a regulator.

Settlement price manipulation

Settlement price manipulation is trading to move an official settlement price, because that price determines margin, portfolio marks and the payoff on contracts many times larger than the trading itself.

Also called settlement rigging, marking the settlement. Observed in futures, commodities, options, bonds. One of the benchmark and cross-market manipulation techniques. 4 enforcement actions in the library.
Updated 2026-09-07

How does settlement price manipulation work?

Every derivatives market has a moment each day when it declares what things are worth.

The settlement price is not merely a closing quotation. It is the number the clearing house uses to mark every open position, to calculate variation margin, to decide whether options finish in the money, and to settle expiring contracts in cash. It is published as authoritative, and the entire market’s plumbing runs on it.

That gives it two properties a manipulator needs. It is decided in a short window, and it determines payments on positions many times larger than the window’s volume.

Hold the referencing exposure. Futures marked to the settlement, options exercising against it, swaps resetting on it, physical contracts priced off it.
Trade into the window. In the direction the exposure requires, aggressively enough to shift the calculation.
Accept the loss on that trading. It is a cost, and it is supposed to be. Paying up in a thin window is expensive by design.
Collect on the exposure. The clearing house does the rest: margin flows, marks change, contracts settle.

The economics invert ordinary trading, which is the family’s defining characteristic and its clearest detection signal. In every other technique the trade is the profit. Here the trade is the price of admission, and the profit arrives from the clearing house the next morning.

The window trade loses. Everything downstream pays.

A worked example with real numbers

A physically settled commodity future, 1,000 units per lot, settling on the volume-weighted average of the final five minutes. The market has traded near $88.40 all day, and the window typically carries 300 lots.

A participant holds 2,600 lots long, marked to today’s settlement, plus 900 lots of call options struck at $89 that expire today.

The window trade. They buy 280 lots aggressively.


Average price paid	$89.90
Pre-window price	$88.40
Cost of paying up	280 × 1.50 × 1,000 = $420,000

The settlement. Their 280 lots are 48% of the window’s volume, pulling the average up.

Settlement without their trade  ≈  $88.44
Settlement with it              ≈  $89.16
Movement                        =    $0.72

Downstream.

Futures mark   2,600 lots × $0.72 × 1,000  =  $1,872,000
Options        900 calls at $89 finish in the money rather than out

Net of the $420,000 burned in the window, roughly $1.45 million, plus whatever the options are worth — on a day when the underlying market did nothing.

Who paid. Everyone short those 2,600 lots posts variation margin they would not otherwise have posted. Everyone short the calls is assigned. The clearing house distributes the money without any view about how the settlement was arrived at, because that is its function.

Note the leverage ratio: 280 lots of trading moved 2,600 lots of exposure, roughly nine to one, plus the options. The larger that ratio the more profitable the scheme — and the more conspicuous, because positions above reporting thresholds are reported daily.

Why is settlement price manipulation illegal?

Three provisions apply, with materially different burdens, and which one a regulator chooses shapes the case entirely.

Section 9(a)(2) of the Commodity Exchange Act, at 7 U.S.C. § 13(a)(2), prohibits manipulating the price of a commodity. This requires proving an artificial price, which means establishing what the price should have been. It is the hardest route and has defeated otherwise strong cases.

CFTC Rule 180.1 requires deception rather than artificiality. Because it is modelled on Rule 10b-5, courts interpret it against securities case law, and it is the CFTC’s preferred route for exactly that reason.

Section 4c(a)(5)(A) prohibits trading that demonstrates intentional or reckless disregard for orderly execution during the closing period. This is the least demanding: it reaches recklessness, and it does not require proving that the settlement was distorted at all.

In securities markets, Exchange Act § 9(a)(2) and Rule 10b-5 cover the equivalent conduct, usually described as marking the close.

Venue rules matter as much as statute, and venue remedies matter more. Exchanges prohibit trading intended to affect settlement and monitor window participation directly. More importantly they hold structural fixes that no regulator can impose as quickly:

Lengthening the window, so more genuine volume must be overcome.
Volume-weighted rather than last-price settlement, which multiplies the capital required.
Trade-at-settlement facilities, so participants who need the settlement price can obtain it without trading in the window at all.
Position limits into expiry, capping the referencing exposure that makes the scheme worthwhile.

Each of these attacks the arithmetic rather than the conduct, and each has been deployed.

Provisions most often charged
Provision	Citation	Primary text
Commodity Exchange Act — manipulation	7 U.S.C. § 13(a)(2)	Read the text
CFTC Rule 180.1 — fraud-based manipulation	17 C.F.R. § 180.1	Read the text
Commodity Exchange Act — disruptive practices	7 U.S.C. § 6c(a)(5)	Read the text
SEC Rule 10b-5	17 C.F.R. § 240.10b-5	Read the text

Which real enforcement actions have alleged settlement price manipulation?

This library holds 4 enforcement actions tagged settlement price manipulation. The table shows the largest by civil penalty together with the most recently filed. Every row links to a page carrying the regulator's own release and, where one was published, the complaint.

Selected settlement price manipulation actions
Action	Agency	Filed	Penalty	Status
CFTC v. Statoil ASA (price manipulation, 2017)	CFTC	2017-11-14	$4m	judgment
CFTC v. Joseph F. Welsh III (price manipulation, 2015)	CFTC	2015-06-20	$500k	judgment
CFTC v. of Attempted Manipulation of NYMEX Crude Oil Futures Contracts (banging the close, 2013)	CFTC	2013-11-26	$400k	judgment

All 4settlement price manipulationactions →

How does settlement price manipulation get detected?

Window participation share. The screening metric: what proportion of the window’s volume came from one participant, against their share of the rest of the session.

Referencing exposure mapping. The decisive step. Large trader reports give regulators the participant’s positions in everything that settles against the price. Testing whether the direction of window trading matched what that exposure required, across many days, is what converts a pattern into a case.

Standalone window profit and loss. Consistent losses in a specific few minutes, session after session, are not a strategy. They are a cost being paid for something else.

Post-settlement reversion. Comparing the settlement against prices shortly afterwards. A settlement that reverts immediately reflected nothing durable.

Date clustering. Concentration on expiry dates, option exercise dates and days of largest exposure.

Trade-at-settlement reconciliation. A participant using the trade-at-settlement facility while also trading the window aggressively in the same direction has arranged to benefit from a settlement they are simultaneously moving.

Participation in the settlement window that is disproportionate to the participant's activity elsewhere in the session.
A referencing position whose value moves with the settlement in the direction the trading pushed it.
Window trading that loses money on its own terms, repeatedly and specifically.
Concentration on expiry dates, option exercise dates and days of largest referencing exposure.
Use of trade-at-settlement volume alongside aggressive window trading in the same direction.

What penalties does settlement price manipulation actually attract?

The numbers below are computed from this site's own case records at build time, not quoted from a secondary source. They change whenever a new action is added to the library.

Actions recorded: 4
Median penalty: $500k
Largest penalty: $4m
Criminal parallel: 0%
Median sentence: —

Computed from 4enforcement actions in our own case library tagged settlement-price-manipulation , filed between 2013 and 2017. Median penalty covers the 3actions where a civil monetary penalty was disclosed; median sentence covers the 0 defendants who received a custodial term. Penalties exclude disgorgement and prejudgment interest, which are reported separately on each case page.

Largest single penalty: CFTC v. Statoil ASA (price manipulation, 2017) .

What are the red flags?

Settlement prices that diverge from the volume-weighted average of the surrounding period.
Repeated volume spikes confined to a published settlement window.
A participant whose window activity appears only on dates when their exposure is largest.

What settlement price manipulation is not

It is not trading at the settlement. Participants who must transact at the official price trade in the window because that is where the price is made.

It is not hedging into the close. Squaring a book before a settlement is ordinary risk management.

It is not a large position. Holding substantial exposure that settles against a price is what derivatives markets are for.

It is not any settlement that moves. Windows are thin and move on ordinary flow. The case rests on the referencing position and the pattern of self-inflicted losses, not on the price change.

Frequently asked questions about settlement price manipulation

What is a settlement price used for?: Marking every open position to market, calculating margin calls, determining whether options are exercised, and settling expiring contracts in cash. One number, published once a day, drives payments across the entire market.
How is this different from banging the close?: Banging the close is the term used for aggressive trading in a closing settlement window, particularly in commodities. Settlement price manipulation is the broader category, covering any official settlement including those derived from other markets or from submitted quotes.
Why is the window so short?: Because a settlement must be timely and objective. Longer windows are harder to manipulate but slower to publish and less representative of the closing state of the market. Venues trade off these considerations explicitly.
What is trade at settlement?: A mechanism allowing participants to agree now to trade at whatever the settlement turns out to be. It lets those who need the settlement price obtain it without trading in the window, which reduces legitimate window volume and makes remaining aggression more conspicuous.
Do clearing houses have a role?: Yes, and a direct one. They calculate margin from settlement prices, so a manipulated settlement forces genuine participants to post cash or liquidate. The clearing house is the transmission mechanism through which the harm reaches everyone else.
Is a volume-weighted settlement safer than a last price?: Substantially. A settlement derived from the volume-weighted average of a window requires far more capital to move than one derived from the last trade. Most venues have moved in this direction for exactly this reason.
What must a regulator prove?: Under the traditional claim, an artificial price and intent to create it. Under Rule 180.1, deception. Under the disruptive practices provision, intentional or reckless disregard for orderly execution during the closing period, which is the least demanding of the three.
Can exchanges act on their own?: Yes, and they do. Adjusting settlement methodology, lengthening windows, imposing position limits into expiry, and disciplining participants under their own rulebooks are all available without waiting for a regulator.

Banging the close — Banging the close is trading heavily during the short window used to calculate a settlement price, in order to move that settlement in favour of a much larger position that references it.
FX fixing — FX fixing manipulation is trading during the short window used to calculate a daily currency benchmark, using advance knowledge of client orders that must be executed at that fix.
Cash versus derivatives schemes — A cash versus derivatives scheme establishes a large derivative position and then trades the smaller underlying market at a deliberate loss, in order to move the reference price the derivative settles against.
Marking the close — Marking the close is trading in the final minutes of a session specifically to move the closing price, which is the price that sets portfolio valuations, margin calls, index levels and derivative settlements.

Terms defined on this page

Settlement Price · Fixing · Mark To Market · Margin · Clearing House · Open Interest

Sources

Commodity Exchange Act § 4c(a)(5) — Cornell Legal Information Institute
CFTC Rule 180.1 — Electronic Code of Federal Regulations
CFTC market surveillance programme — Commodity Futures Trading Commission

Reviewed September 7, 2026. Every statute link points at the primary text. If something here is wrong, tell us — corrections are logged in public.