Why Forex Spreads Widen: News, Rollover and Liquidity

A familiar currency pair can suddenly become more expensive to trade even when its price chart looks relatively quiet. The reason may be a wider spread: the distance between the quoted buying and selling prices has increased.

Forex spreads can widen when liquidity becomes thinner or pricing risk increases. 

News releases and market openings or closings are common settings for this behaviour, but the exact quote also depends on the instrument and pricing arrangement. [1]

The practical question is not just why the spread changed. It is how that change affects the price at which your order can be executed, the valuation of an existing position and any attached stop instructions.

Start with the two executable prices

The bid is the quoted selling price and the ask is the quoted buying price. The spread is the ask minus the bid. A chart based on one side of the quote does not display the full difference between them. [2]

Consider two hypothetical EUR/USD quotes:

Both quotes have the same midpoint, 1.10010. Nevertheless, the cost of buying and immediately selling at those prices is different.

Assume a 10,000-euro position and no price change between the hypothetical entry and exit. The bid-ask difference corresponds to $1.20 in the first case and $4.00 in the second, before other charges. This calculation isolates the spread; it is not a quote for DecodeFX pricing or a prediction of execution.

Why thinner liquidity can mean a wider spread

Liquidity concerns the ability to transact without causing a large price impact, not simply whether a chart is updating. When fewer attractive buy and sell quotes are available, the gap between the two sides can increase.

Market-makers also need to manage inventory and the cost of hedging risk. If those risks or costs rise, quoting narrowly can become less attractive. BIS analysis describes how reduced market-making capacity and greater volatility can reinforce wider bid-ask spreads. [3]

For a trader, the implication is practical: an actively moving chart is not proof that a particular size can be filled at a tight spread. Assess the executable quote and order conditions, not the appearance of activity alone.

Why news can change spreads before and after a release

A scheduled release can introduce uncertainty before the new information becomes public. Once it arrives, prices and available quotes may adjust quickly. Liquidity and volatility are related but not interchangeable: high activity does not guarantee a narrow spread at the moment you submit an order.

Published broker explanations identify major announcements as one setting in which changing liquidity and pricing risk can widen spreads. [1] The size and duration of a change are not fixed, so there is no universal rule that conditions return to normal a certain number of seconds after an announcement.

A useful preparation step is to identify releases relevant to the currencies in the position. That supports planning; it does not tell you whether the announcement will produce a profitable trade.

What happens around rollover and session changes?

Trading participation can change during the transition between the US and Asian sessions. During thinner conditions around rollover, spreads can become wider and execution can become less predictable. This is a market-condition risk, not a promise that every instrument experiences the same daily pattern. [4]

Check the broker's instrument schedule and relevant notices. Do not convert an assumed "rollover hour" into your local time without checking the stated time zone and daylight-saving treatment.

Spread widening and overnight financing are different. The first changes the distance between buy and sell quotes. The second is a carrying adjustment governed by the applicable account and product terms. A position may be affected by one, both or neither at a particular moment.

Can a wider spread trigger a stop-loss?

For typical over-the-counter Forex positions in MT5, stop-loss conditions for a long position are checked against bid, while conditions for a short position are checked against ask. This matters when a chart displays only one quote side. [5]

Imagine a hypothetical short position with a stop at 1.10030. If bid is 1.10000 and ask moves from 1.10010 to 1.10035, the ask has passed the stop level even though the bid has not risen. A bid-only chart would not, by itself, explain what happened.

The trigger and the execution are separate matters. A standard stop does not guarantee a fill at the exact requested level, especially where prices gap or available liquidity changes. [4]

After an unexpected execution, review the relevant bid and ask information, the timestamp and the order record. Do not infer a pricing error, or dismiss the possibility of one, from a single chart screenshot.

Spread widening is not the same as slippage

Spread describes the distance between simultaneous buy and sell quotes. Slippage describes a difference between the price expected or requested and the price actually executed. Both can be relevant to the same trade, but they are not the same measurement. [4]

For a completed trade, calculate the price result from the actual executed entry and exit prices. That difference already includes the effect of trading on the relevant quote sides. Do not deduct a separate estimated spread a second time. Review commissions and financing as separate entries where applicable.

Comparisons also need a consistent basis: the same instrument, account type, volume, time and units. A minimum advertised spread, an average spread and a single quote during a news event answer different questions.

A practical response to an unusually wide spread

Before submitting a new order, check the live bid and ask, convert their difference into money for the intended position, and review relevant calendar events and session information. Compare the result with the assumptions behind your trade plan.

For an existing position, review its quote-side valuation, stops and available margin. Do not automatically widen a stop, add funds or increase the position just to accommodate a change in the spread. Those are separate risk decisions, not technical fixes.

If a quote or execution remains unclear, save the full symbol, server, timestamp and order details, then ask support to investigate through a private channel. Evidence makes the question easier to resolve.

Frequently asked questions

Does a low spread mean a trade is low risk?

No. The spread describes one element of dealing cost. It does not measure the size of future price moves, the suitability of the position or the likelihood of profit.

Can spreads widen without a major news release?

Yes. Session changes, reduced participation and instrument-specific conditions can also affect quoting. A calendar cannot identify every possible liquidity disruption. [1][4]

Should I wait for a fixed number of minutes after news?

Build a cost-aware routine

For a complete preparation routine, learn how to read actual, forecast and revised calendar figures, then review MT5 order triggers and slippage. The total trading-cost guide explains how spread, commission and swap fit together.

Use the DecodeFX Economic Calendar to identify scheduled events, and review the existing forex spreads guide for the underlying cost calculation. Treat both as preparation tools, not signals to trade.

Risk notice: This article is general education, not personal investment advice or a recommendation to trade. Quotes and calculations are hypothetical. Leveraged CFDs can cause rapid losses. Standard stop-loss instructions do not guarantee an execution price, and applicable conditions vary by entity, jurisdiction and account.

Sources

[1] OANDA, Impact of market conditions on spreads. Used for the explanation of market conditions, not as evidence of DecodeFX's pricing or policies.

[2] MetaQuotes, Market Watch: bid, ask and spread.

[3] Bank for International Settlements, Shifting tides: market liquidity and market-making in fixed income instruments. A source on general market-making mechanisms, not a study of DecodeFX quotes.

[4] FTMO x OANDA, Slippage and order execution. Used for general rollover and execution mechanics, not account-specific terms.

[5] MetaQuotes, Types of orders: bid/ask trigger conditions.