What this publication is for

The fill is not the price.

Between deciding to trade and owning the position, money leaves in a dozen places — some of them quoted to you, most of them not. This is a running account of every one: what it is, when it is charged, who sets it, and whether you can do anything about it.

We are not a broker and we sell nothing. Where a figure depends on the firm you trade through, we say so rather than quoting one as if it were universal.

The ledger · 12 costs

Every charge and friction between your decision and your fill.

Trading costs, what each means, when it happens, who controls it and whether a trader can reduce it.
Cost	What it means	When	Who sets it	Reduce it?
The spread	The gap between the price you can buy at and the price you can sell at.	Every time you open or closeAny time	Your broker	PartlyChoose when you trade and who you trade through; you cannot trade without crossing it.
Bid and ask	The two live prices behind every quote — one to sell into, one to buy from.	Continuously, before you do anythingAny time	The market	NoIt is the structure of a quoted market, not a charge.
Commission	A stated fee per trade or per lot, charged on top of the spread.	On opening, and usually again on closingAny time	Your broker	PartlyIt is quoted up front, so it can be compared between firms before you commit.
Overnight financing	A daily charge or credit for holding a leveraged position past the cut-off.	Every night you stay inWhile you hold	Your broker	PartlyHold for less time, or size smaller. For a long hold it can exceed the spread many times over.
Slippage	The difference between the price you asked for and the price you got.	At the moment of executionAny time	The market	PartlyOrder type and timing change your exposure to it. Nothing removes it.
Spread widening	The spread growing — sometimes many times over — around news and session edges.	Releases, rollover, thin hoursAny time	The market	YesIt is largely predictable. Most of it is avoided by not trading into it.
Thin liquidity	Too few resting orders to absorb yours at one price, so it fills across several.	Off-session hours, small instruments, large sizeAny time	The market	YesTrade when the book is deep, or in size the book can absorb.
Your choice of order	What you instruct the broker to prioritise — speed, or price.	Every order you placeAny time	You	YesThe one cost on this page that is entirely yours. It is also the least understood.
Gapped stops	A stop filling well past its level because price never traded in between.	Gaps, news, weekend opensGetting out	The market	PartlyA stop is an instruction to exit, not a promise of a price. Guaranteed stops cost extra.
The costs nobody quotes	Inactivity fees, withdrawal charges, currency conversion, data subscriptions.	Monthly, or on withdrawalAny time	Your broker	YesAll disclosed somewhere. Almost never on the page advertising the spread.
Cost relative to your style	The same costs weigh completely differently on a scalper and a position trader.	Across every trade you makeAny time	You	YesMatch the style to the cost base rather than fighting the cost base.
Execution quality	How faithfully, and how fast, your broker turns an instruction into a fill.	Every order, mostly invisiblyAny time	Your broker	PartlyRarely published in a comparable form, which is itself worth knowing.

The spread
The gap between the price you can buy at and the price you can sell at.
When
Every time you open or close
Who
Your broker
Reduce
PartlyChoose when you trade and who you trade through; you cannot trade without crossing it.
Bid and ask
The two live prices behind every quote — one to sell into, one to buy from.
When
Continuously, before you do anything
Who
The market
Reduce
NoIt is the structure of a quoted market, not a charge.
Commission
A stated fee per trade or per lot, charged on top of the spread.
When
On opening, and usually again on closing
Who
Your broker
Reduce
PartlyIt is quoted up front, so it can be compared between firms before you commit.
Overnight financing
A daily charge or credit for holding a leveraged position past the cut-off.
When
Every night you stay in
Who
Your broker
Reduce
PartlyHold for less time, or size smaller. For a long hold it can exceed the spread many times over.
Slippage
The difference between the price you asked for and the price you got.
When
At the moment of execution
Who
The market
Reduce
PartlyOrder type and timing change your exposure to it. Nothing removes it.
Spread widening
The spread growing — sometimes many times over — around news and session edges.
When
Releases, rollover, thin hours
Who
The market
Reduce
YesIt is largely predictable. Most of it is avoided by not trading into it.
Thin liquidity
Too few resting orders to absorb yours at one price, so it fills across several.
When
Off-session hours, small instruments, large size
Who
The market
Reduce
YesTrade when the book is deep, or in size the book can absorb.
Your choice of order
What you instruct the broker to prioritise — speed, or price.
When
Every order you place
Who
You
Reduce
YesThe one cost on this page that is entirely yours. It is also the least understood.
Gapped stops
A stop filling well past its level because price never traded in between.
When
Gaps, news, weekend opens
Who
The market
Reduce
PartlyA stop is an instruction to exit, not a promise of a price. Guaranteed stops cost extra.
The costs nobody quotes
Inactivity fees, withdrawal charges, currency conversion, data subscriptions.
When
Monthly, or on withdrawal
Who
Your broker
Reduce
YesAll disclosed somewhere. Almost never on the page advertising the spread.
Cost relative to your style
The same costs weigh completely differently on a scalper and a position trader.
When
Across every trade you make
Who
You
Reduce
YesMatch the style to the cost base rather than fighting the cost base.
Execution quality
How faithfully, and how fast, your broker turns an instruction into a fill.
When
Every order, mostly invisibly
Who
Your broker
Reduce
PartlyRarely published in a comparable form, which is itself worth knowing.

How to read it

Who sets it matters more than how big it is

A cost your broker sets can be compared and changed by moving. A cost the market sets cannot, at any firm. They are different problems and the ledger separates them.

5 of 12 are genuinely reducible

The rest you influence at the margin or simply pay. We would rather say so than sell a technique for removing something that cannot be removed.

No figures without a source

Spreads, commissions and financing rates vary by broker, instrument and hour. Anywhere we give a number, it is cited. Where we have none, it says so.

The long answers

All writing

11 of the 12 rows above are written up in full. A row with no article still answers its four questions — it is simply not yet explained at length.