The recommendations of Wall Street analysts are often relied on by investors when deciding whether to buy, sell, or hold a stock. Media reports about these brokerage-firm-employed (or sell-side) analysts changing their ratings often affect a stock's price. Do they really matter, though?Let's take a look at what these Wall Street heavyweights have to say about JPMorgan Chase & Co. (JPM) before we discuss the reliability of brokerage recommendations and how to use them to your advantage.JPMorgan Chase & Co. c ...