Interactive visualization of Netflix stock is difficult to understand

I found an interactive visualization of data associated with Netflix stock on Yahoo Finance. This visualization contains a lot of information, and, in my opinion, is difficult to interpret. First of all, the visualization has two separate plots that measure two separate things on the same set of axes. One of them is a line plot that shows trends in stock price. This plot is relatively simple to interpret, provided you know that the stock price is measured in dollars (the chart doesn't indicate this).  The other is a bar plot that shows volume of stocks sold, and it really shouldn't share the same vertical axis as the first plot considering volume here is measured in number of shares (which goes into the millions). The bars in the plot are colored either red or green, but there is no indication as to what the colors mean, as there is no legend anywhere. There is a lot of interactivity here, though. You can compare trend lines with other stocks, change the time scale, and move your cursor across the line plot to see statistics associated with that point in the line. For people who know a lot about stocks and related statistics, this might well be a simple chart to use and understand. For others, it's much less simple.