EURUSD trades a 0.6 pip spread all session, tight and boring, until an economic release crosses the wire and the spread jumps to 4 pips for ninety seconds before settling back down. A trader who enters right at that moment on a market order has already paid nearly seven times the normal cost of the trade before price has moved an inch in either direction. Spread is not a fixed number quietly ignored once you know it. It moves, sometimes violently, and the moments it moves are exactly the moments a lot of traders feel the strongest urge to act.
What actually makes a spread widen
A spread is the gap between the price a market maker will buy at and the price they will sell at, and it widens whenever the market maker's own risk of holding that position goes up. Three conditions do this reliably: scheduled news such as NFP, CPI or an FOMC decision, where prices could gap in either direction the instant the number prints; thin liquidity, most commonly right after the New York close and through the early Asia session, when far fewer market makers are actively quoting; and the rollover hour itself, roughly 5 PM New York, when the settlement process and that same thin liquidity overlap.
What a wide spread actually costs
The cost is not abstract. A EURUSD position sized to risk 1%, $100 on a $10,000 account, against a 20-pip stop assumes a normal spread of well under 1 pip is baked into that math. Enter the same trade during a 4-pip spread and the position effectively starts three-plus pips underwater versus a normal fill, which on a tight scalp can be a third of the planned risk gone before the trade has even had a chance to work. On gold, where spreads can run from around 20 cents in calm conditions to several dollars during a US data release, the effect is proportionally larger.
The moments worth actually standing aside for
The clearest rule: do not place a fresh market order in the sixty seconds around a scheduled high-impact release. The spread during that window is compensating the market maker for genuine uncertainty, not gouging anyone, but it makes the trade mathematically worse regardless of intent. The same applies to the few minutes around 5 PM New York rollover and to the thin early-Asia hours where a single moderate order can move price further than it should, dragging the spread wide simply because there is less depth to absorb it.
Reading the spread before you click
Most platforms display the live spread on the order ticket itself, and checking it for half a second before entering is a habit worth building alongside checking the stop distance. A spread noticeably wider than the pair's normal range, EURUSD showing 3 pips when it normally runs under 1, gold showing $2 when it normally runs 20 to 30 cents, is a direct signal that either news is imminent or liquidity has thinned, and either way the trade is better placed a few minutes later once the number settles back down.