Matthew

Jesus concludes the Olivet Discourse with a parable. That is to say, Mark's account of the Discourse ends with a parable. Matthew's ends with multiple parables that continue into the next chapter. Luke's account ends with an exhortation but no parable. It's complicated.
The parable at the end of Matthew 24 has a similar setup to the one at the end of Mark 13 but is different. In fact, Luke has both parables, but they are included back in Luke 12, not in the version of the Discourse found in Luke 21. Like I said, complicated.
One way or another, the Discourse ends with the message that followers of Christ should stay awake, do our duty in God's household, and live anticipating the return of our Master.