Leave a large gold position open overnight and the broker charges you for the privilege, every single night, whether the trade is working or not. It is a small number attached to a single ticket, and it is also the exact reason some strategies that look profitable on paper quietly lose money in practice once the true cost of holding is added back in.
Overnight financing is not a trap or a hidden fee designed to punish you. It is simply the mechanical cost of holding a leveraged position past the point where the market normally settles it, and every instrument charges a different version of it.
What overnight financing actually is
Most leveraged instruments are effectively borrowed exposure: you control a much larger position than your account balance would otherwise allow, and the difference is functionally financed. Hold that position past the daily rollover point, typically around 5:00 PM New York time for forex, and you pay or receive a financing charge for one more day of that borrowed exposure. On forex pairs this is called swap and depends on the interest rate differential between the two currencies: holding a currency with a higher rate against one with a lower rate can actually pay you overnight, while the reverse costs you. On indices and metals, the equivalent charge usually reflects the cost of carrying the position at prevailing short-term rates, and it is almost always a cost rather than a credit.
How the numbers actually add up
The charge itself is often described as small, a few dollars per standard lot per night, and on a single overnight hold it usually is. The problem is that it compounds with every night a position stays open, and it compounds fastest exactly when a trade is not working, the losing position you are reluctant to close and holding out of hope. A EURUSD position held for two weeks while a hoped-for reversal fails to arrive can rack up rollover charges that meaningfully worsen an already bad trade, on top of whatever the price movement itself cost. Gold and oil positions held for extended periods face their own version of this drag, and it is rarely factored into a trader's mental math when they decide to hold it a bit longer.
The weekend and holiday multiplier
Most brokers charge extra financing over the weekend to account for the two or three days markets are closed, often triple the normal daily rate applied on a Wednesday night to cover Thursday, Friday and the weekend in one charge, depending on the broker's convention. A position held into a long holiday weekend can accumulate several days worth of financing in a single overnight charge. None of this is hidden; it is disclosed in every broker's fee schedule, but it is easy to ignore until a swing trade that seemed cheap on the entry ticket turns out to have handed back a meaningful chunk of profit to financing costs alone.
The intraday trader's clean-slate advantage
An intraday trader who closes every position before the daily rollover simply never pays this cost, on any instrument, ever. That is not a minor convenience, it is a structural edge over anyone holding positions past 5:00 PM New York: no financing charges to track, no weekend multiplier to worry about, and no need to model an unpredictable ongoing cost into every trade's expected value. The intraday trader's entire risk and cost picture resets to zero at the end of every session, which is precisely why flat by close is not just a risk management habit, it is also, quietly, a cost management one.