Snapshot of a Fund

As far as I understand rate of return = (gain or loss)/total amount put in

But looking through my 401K, the rate of returns don't seem to be matching if money was gained or loss. For example, graph is saying "cumulative personal rate of return" is -3% for my entire profile of about 18 months. (annualized return -1.76%) However, I have gained money (not much money hah! $106) over this time period.

I think I must be misunderstanding the definition of Cumulative Personal Rate of Return. Or it has something to do with when money as put in... and how it did? As to why analysis is showing negative rate of return.

Sorry if this is an obvious question, or the like.. but I've spent hours trying to figure this out. And now it's giving me a headache. Thanks kind people.

The picture is another example of rate of return and actual margins not adding up for me.