Hmmm..what issue did you show a $42 loss on? I can see if there is anything unusual there

Two rare occurrences that might cause this. One is that there were duplicate listings of the same comic in the system, each with a different value, and an administrator merged the two listings...your comic would have moved into that merged listing and if it didn't have the same value it wouldn't show as a value change. Two, when making a valuation change an administrator either didn't like the value the algorithm spewed out for all grades and manually changed a few, or an error was made and corrected...you would only see the change from the most recent adjustment. This is not something I would expect to see on a regular basis though, but it does happen

I track the value of my collection every day or two. Sometimes I'll see that my collection has increased in value by, say, $50, without adding any comics to the database. I go see which books have changed in value and their individual changes don't add up to $50. It might add up to only $20. Why am I not seeing everything? Am I doing something incorrectly?