What does this say about the real estate market?

Quite a few people in my neighborhood have moved out of their homes and literally someone has moved in overnight. I can only guess they are moving out and renting their homes to other people.

Because it's done so fast and without notice, I can't help but wonder if people are doing this to avoid losing their homes. If that is the case, it's good that they are trying to keep their homes but it bad that they aren't screening the people who are moving into their homes. They aren't using realtors. It is literally an overnight process as if they advertise on Craig's List or something similar. Suddenly you see a different set of cars in the driveway or a different race of people in the yard.
Added (1). Please focus more on the question and less on the phrase "different race of people." The point was to show it was an obvious change in occupants (not just friends visiting). I used that phrase because I didn't want the comments to turn into a thread of race bashing. By race I mean the same as any job application.

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