This is not a bug per se, but the prices on the Market Price Graphs for very expensive items (1 bil or more) are cut off, so that it becomes impossible to read (at least in any sort of meaningful way, except to tell that the prices are exorbitant...).
For example, under the listing for Merry Belle, which averages 18-20 bil:
I currently use a Mac, with both Chrome and Safari (the issue occurs on both browsers) and Flash 14.0.0.125