Last week, I had the following exchange with a close friend: Him: I think we should buy Netflix stock. Look at how much it went down! Me: Now that’s a terrible thing to say before buying a stock. Him: I have the utmost faith in the company. If you’ve been reading Investment of the Week for a while, you can guess what I said next. Me: The company is not the stock! You’ve probably heard that before–I know I’ve heard my father say or write it hundreds of times–but my friend isn’t an investor, so I had to explain...