A news filter tells an EA to stand aside when the market is about to get violent. For a few minutes around a big release — the US jobs report, an inflation print, a central-bank decision — spreads blow out, fills go wrong and prices gap. A filter pauses the strategy through that window so it does not trade into the chaos. It is a blunt tool, and like any blunt tool it costs you something for the protection it gives.
What it is
A news filter is a setting inside an EA, or a small add-on, that stops it opening — and sometimes managing — trades around scheduled high-impact news. It is not predicting anything. It simply knows that at 13:30 London time on the first Friday of the month the US employment figures land, and that the minutes either side are a bad time for an automated strategy to be placing orders.
Why it matters
High-impact releases do specific, measurable damage to the conditions an EA relies on:
- Spreads widen. A pair that normally costs half a pip to trade can jump to five or ten pips as liquidity vanishes.
- Slippage. Your order fills at a worse price than it asked for, because the market moved while the order was in flight.
- Requotes. On some brokers the price you clicked is gone before the trade is accepted, and you are asked to try again.
- Gaps. Price can leap straight through a stop loss, closing you out well beyond the level you set.
A strategy tested in calm conditions can look profitable right up until a single NFP release hands it a week of losses in ninety seconds.
How it works
A news filter needs two things: a list of when news happens, and a rule about what to do around it. The first comes from an economic-calendar feed — a schedule of upcoming releases tagged by importance and country. The second is a time buffer, usually set in minutes either side of the event:
Pause window = [event − buffer] to [event + buffer]
Set a 30-minute buffer around a high-impact release and the EA stops opening trades half an hour before, stays out through the announcement, and resumes half an hour after. You choose which events count — most traders filter only the high-impact releases and ignore the minor ones — and how wide the buffer runs.
The trade-off
Standing aside is not free. The same releases that cause the damage also cause the biggest real moves, and a strategy built to ride volatility may make its money precisely when the filter has it sitting on the bench. A filter that is too cautious — a two-hour buffer around every minor event — can quietly strip out most of an EA's edge. Too narrow and it fails to protect you at all. The right width depends on what the strategy does, and it is worth testing both with and without the filter rather than assuming it always helps.
Built-in versus manual
Some EAs ship with a news filter and their own calendar feed built in. Others expect you to do it yourself — close positions or disable the EA by hand before a release, then switch it back on afterwards. Manual works until the one Friday you forget, or you are asleep through a release in another session. A built-in filter is more reliable, but only if its calendar is current. A feed that has stopped updating protects nothing, and you would not necessarily know it had stopped.
What to check
- Is the calendar actually updating? A stale feed is worse than none, because you trust it.
- Does the buffer match the strategy? A scalper and a swing EA need very different windows.
- Did the EA really pause? Confirm it sat out the last big release rather than assuming it did.
The Karnek note
A news filter only protects you if it is actually working, and a stale calendar or a silently stopped EA looks exactly like one that is behaving. Karnek watches whether each EA is running and trading as it should, and alerts you the moment one goes quiet — so a filter jammed on, or an EA that died before the release, does not cost you a week before you notice. It reads read-only from the terminal and can never trade the account.
Written and reviewed by the Karnek Research team. Last updated August 2026.
Educational content only - not financial advice. Past performance does not predict future results. Trading carries significant risk.