Sometimes the price seems to have reached the level you set, but the alert didn't go off. This usually comes down to how alerts are checked against live ticks.
Alerts are checked on live ticks
An alert triggers when the price reaches or crosses your set level on a live tick. The exchange processes hundreds of transactions (ticks) every second, and the alert engine checks against the ticks it receives.
Because there are so many ticks, one can be missed. If the price moves through your level very quickly and the exact tick at that level isn't captured, the alert may not trigger — even though, looking back at the chart, the price appears to have touched it.
Other things to check
- "Equals to (=)" condition — if you set the condition to equals to (=), the price has to tick at exactly that value. In a fast move it can jump across without an exact match. For a level you simply want the price to reach, use greater than, equals to (≥) or less than, equals to (≤) instead.
- The alert may have already triggered — an alert notifies you once and then becomes inactive. If it already fired earlier, it won't trigger again until you edit and reactivate it.
Good to know
- This is the same reason a chart may not show a wick at a price your order reacted to — see Why was my stop-loss triggered without the trigger price being hit on the chart?.
- To review or reactivate your alerts, see How to modify or delete an alert.