Formatting chart data to improve readability

Hey y'all, I'm new here, so I think my question is pretty easy for some of you veterans...

Essentially my issue is with the formatting. I need to create a line chart of stock prices from 1/1/2009 to present. There are 5 firms, each with VERY similar returns. The issue is not with getting the data into chart form, the true issue lies with the format of the data.

It is all clustered and not very easily understood (there are 5 separate lines). I have tried numerous formatting methods, and I was wondering if anyone here could give me some advice?

Thanks a lot!