Alerts, and the setting everyone gets wrong
Set an alert that fires when you meant it to, not fifty times in an afternoon.
An alert watches a condition and notifies you. The condition can be a price, an indicator crossing something, or a drawing being touched. Creating one: right-click on the chart at the level → 'Add alert', or Alt+A for the current symbol.
The trigger frequency setting
| Option | Fires | Use when |
|---|---|---|
| Only once | First time the condition is true, then deletes itself | A level you only care about the first time it is reached |
| Once per bar | The instant the condition becomes true inside a bar | Rarely. It fires on prices that may not survive the bar. |
| Once per bar close | Only when the bar closes with the condition true | Almost always. This is the honest one. |
Key idea
'Once per bar close' is the correct default for anything based on an indicator, and it is not the platform's default. Indicators are recalculated on every tick while a bar is open — so an alert on an unclosed bar can fire on a crossover that un-crosses two minutes later. Same phenomenon as repainting, seen from the other side.
Common mistake
Alerts on a level with no expiry date and no note. Six weeks later your phone buzzes at 3am and you have no idea why you cared about $61,400. Always write the reason in the alert message — 'BTC weekly resistance from March, watch for rejection' — because the alert is the only thing that survives your memory.
Tip
With three price alerts on the free plan, treat them as a scarce resource: they belong on levels that would change what you do, not on levels you are curious about. Scarcity is a feature here.
Check yourself
You set an alert for 'RSI crosses above 30' with 'Once per bar'. On a daily chart, what can happen?