There are a number of means by which a test may end. These are:
Test reaches scheduled End Date.
The test ends automatically at the date and time specified in the test schedule.
User manually ends test.
You can manually end a test from the A/B Testing screen by clicking on the action cog for the test you wish to end and selecting Stop test from the command list, or by clicking the Stop Test button on the Results screen for the currently active test.
If a user manually ends a test, the test status changes from In Progress to Incomplete.
A Site publish event occurs.
The test ends automatically if any Sites are published while the test is in progress. This happens whether the Site is published by a user clicking the publish button for that Site, or by an auto publish that occurs after certain related events. For more information, please refer to the Publishing and A/B Tests section of this document.