Hey there 👋🏻,
A sequence ends ❌ when all the emails along with follow-ups and tasks have been completed.
You can keep the sequence in "Running" status by checking off "Make it Evergreen Sequence" in Sequence Settings.

Once this is enabled , if the source block matches with more leads in future then they are automatically added to sequence.
For example:
👉🏻 If you have used a list and add more leads to the list, leads are automatically added to sequence.
👉🏻 If you have used a segment source based on events or SalesBlink Variables, when new lead will match the segment - they will be added to sequence automatically.
👉🏻 If you have used CRM Integration source block, any leads who are added to CRM according to your settings - they will be added to the sequence.
Hope this answers your question ✨