So, let's look at the facts. For this I'll turn to Philip Elmer-Dewitt of the Apple 2.0 blog, who has been compiling data on all the top professional and amateur Apple analysts over the past four years, which ranks them based on accuracy over specified periods. And the interesting thing is the data is all over the place. An exhaustive study would likely show that any analyst has an equal shot in any period of outranking the next. At any time, an analyst might release a investor note that could affect Apple's price and in turn, your position...something you never figured into your analysis. So, consider that brokerages employ these spokespersons, who play reckless with our fortunes.
Let's consider the methods analysts use to compute the value of Apple. But before I get into their flawed methods, let me preface with the fact that most analysts covering Apple don't even use Apple products. Ask yourself - how many times have you tried to make sense of an analyst's statement, where they've demonstrated a complete misunderstanding of Apple culture, the ecosystem, or the fan base. This isn't universal of course - some analysts are very knowledgeable and huge Apple fans, but even a respected Apple bull like Gene Munster ranks only in the middle of the pack, well behind several amateur analysts. Some of the most influential analysts rank near the bottom of the pack, like Charlie Wolf and Kathy Huberty.