up and down green and red arrows to indicate value changes to games in a collection or seller listing.

I'm pretty new to the site and this is the 1 thing I've wished for since I started building up my collection.  

Right on, it sure would be helpful even to gauge what to add to our collections.

I hope for this every day 

common... this would be so easy to add.. and it's been long enough... 

A valuable tool for any collection 

I for one, like to know what's in my collection that's losing, or gaining value 

This is a good feature request, but how long do you want this evaluation?

Not sure what you mean by how long. Just 2 arrows, green up, red down say on changes in increments of one dollar?

Open to suggestions.

This is a fantastic idea. I hope it gets implemented.

stashmycomics had a similar feature when I used that. It would show you the biggest % increases and decreases in value for the period. Increases in green and decreases in red. It really helped me know when to buy or sell a comic based on trends. Seeing a comic explode by 400% in value was always exciting.