Unlike a spread, which you pay once per round trip, overnight financing is a subscription: it charges every night you keep a leveraged position open, on the full notional value — not on the small margin you posted.
It is the least visible line of the cost bill precisely because it never appears on a trade confirmation. It appears in your account balance, a little at a time.
Overnight financing = notional value × daily rate × nights held. It applies to margined longs, and usually to shorts as well (borrowing has its own cost). The daily charge looks tiny; multiplied by weeks of holding it becomes a meaningful drag that raises your breakeven. Cash positions without leverage pay none — which is why holding-period decisions should always ask: am I paying rent on this position?
How the charge is calculated
The formula is simple: notional value × daily rate × nights held. The daily rate is the annual rate divided by 360 or 365, depending on the broker. The key word is notional: financing applies to the full exposure your position controls, not the margin you deposited.
On a $10,000 notional position at an assumed 7% annual rate, one night costs about $1.90. Posted margin might have been $1,000 — which means the charge is 0.19% of your margin every night, or nearly 6% of it per month. Expressing the cost against margin, against notional, and against your expected move are three different questions; confusing them is how “cheap leverage” gets expensive.
Rates float. Most brokers index financing to a reference rate plus or minus a markup, so the daily charge moves when central-bank rates move. A rate that was negligible in one rate environment can quietly become a real drag in another.
Shorts pay rent too — sometimes more
A common misconception is that financing only burdens long positions. A short position borrows the asset to sell it, and borrowing has a fee — for hard-to-borrow names, the fee can dwarf ordinary financing. The direction of your view and the direction of your rent are two separate questions.
Derivative products wrap the same economics differently: futures embed the cost of carry in the price, and some products adjust rates daily or apply triple charges around specific calendar dates. The mechanics vary by product; the principle does not. If a position controls more value than you posted, someone is financing the difference — and that someone is you.
What the rent changes
Your breakeven moves every night. A position that is flat after one night is underwater by the financing after thirty. The longer the hold, the larger the move your thesis must produce just to cover rent.
It converts time into an adversary. With unleveraged cash positions, waiting is free. With financed positions, every day of waiting has a price — which quietly pressures you to act before your reasons have changed. That pressure is a risk, not a feature.
It reshapes what “cheap” leverage means. Comparing two leveraged products on headline leverage alone ignores financing. The product with lower margin requirements often charges for the privilege night after night.
If your expected move is measured in percent and your holding period is measured in weeks, do the multiplication before entering: expected move versus expected financing. If the two are close, the position is not an investment in a view — it is a subscription to hope.
- I know the notional value my position controls, not just the margin posted.
- I know my broker’s financing rate and which reference rate it tracks.
- I have multiplied the daily charge by my realistic holding period.
- For short positions, I have checked the borrow cost separately.
- My expected move is meaningfully larger than the total expected financing.
Frequently Asked Questions
Is financing charged on weekends?
Practice varies: some brokers charge only trading days, others charge calendar nights — sometimes with an enlarged charge on one day to cover the weekend. Check your broker’s method before assuming the daily figure is the whole story.
Can financing ever be credited to me instead of charged?
Yes, in some products and directions the rate can be positive for the holder — commonly seen in currency positions when interest-rate differentials favor the direction held. Treat it as a byproduct of the position, not as a reason to open one.
Does financing apply to unleveraged stock holdings?
No. If you paid the full price and your broker is not lending you anything, there is nothing to finance — the cost of holding is opportunity cost, not interest. Financing exists exactly where value is controlled beyond the cash posted.
