Tricks to increase home value on websites like Zillow?

[Josh Barnett]

I want to know if I am just crazy, or is there a way to alter your house value on websites like Zillow, realtor, redfin...

We purchased our house in Colorado Springs in May 2018 ($313k). I regularly watched our house value on websites like Zillow, Redfin, and Realtor as well as house values throughout the neighborhood, tracking the highest priced houses in particular.  Our house mostly hovered around 320-325 and the highest price houses were around 330-335 during this time.  My house is currently 335 now.

In NOV 2018 a house right down the street went on sale for $399.  My wife and I made fun of it's ridiculousness. It is so crazy, it will never sell.  Especially because it is winter where the market in the area slows down.

However, when it went off the market at the beginning of the year, the value stayed up!  Out of nowhere this house value increased 100K in a month. Realtor.com shows the actual jump. Redfin seemed to "backdate" the home value on its monthly tracker to smooth out the line.   

The house then went back on the market a month or so later, and had the "value" to backup the high price.  It sold for $385 and is by far the highest value house in the neighborhood.  

How did they make this happen? Why did Redfin seem to change the value history?

https://www.realtor.com/realestateandhomes-detail/5045-Fabray-Ln_Colorado-Springs_CO_80922_M25741-40258#photo2