【正文】 外文翻譯 ： Stock:Expected and unexpected return To begin, for concreteness, we consider the return on the stock of a pany called Flyers. What will determine this stock’s return in, say, the ing year? The return on any stock traded in a financial market is posed of two parts. First, the normal, or expected, return from the stock is the part of the return that shareholders in the market predict or expect. This return depends on the information shareholders have that bears on the stock, and it is based on the market’s understanding today of the important factors that will influence the stock in the ing year. The second part of the return on the stock is the uncertain, or risky, part. This is the portion that es from unexpected information revealed within the year. A list of all possible sources of such information would be endless, bet here are a few examples: News about Flyers research Government figures released on gross domestic product (GDP) The results from the latest arms control talks The news that Flyers’s sales figures are higher tan expected A sudden, unexpected drop in interest rates Based on this discussion, one way to express the return on Flyers stock in the ing year would be: Total return = expected return + unexpected return R = E (R) + U Where R stands for the actual total return in the year, E(R) stands for the expected part of the return, and U stands for the unexpected part of the return. What this says is that the actual return, R, differs from the expected return, E(R), because of surprises that occur during the year. In any given year, the unexpected return will be positive or negative, but, through time, the average value of U will be zero. This simply means that on average, the actual return equals the expected return. Risk: systematic and unsystematic The unanticipated part of the return, that portion resulting from surprises, is the true risk of any investment. After all, if we always receive exactly what we expect, then the investment is perfectly predictable and by definition, riskfree. In other words, the risk of owning an asset es from surprisesunanticipated events. There are important differences, though, among various sources of risk. Look back at our previous list of news stories. Some of these stories are directed specifically at Flyers, and some are more general. Which of the news items are of specific importance to Flyers? Announcements about interest rates or GDP are clearly important for nearly all panies, whereas the news about Flyers’s president, its research, or its sales is of specific interest to Flyers. We will distinguish between these two types of events, because, as we shall see, they have very different implications. Systematic and unsystematic risk The first type of surprise, the one that affects a large number of assets, we will label systematic risk. A systematic risk is one that influences a large number of assets, each to a greater of lesser extent. Because systematic risks have marketwide effects, they are sometimes called market risks. The second type of surprise we will call unsystematic risk. An unsystematic risk is one that affects a single asset or a small group of assets. Because these risks are unique to individual panies or assets, they are sometimes called unique or asset specific risks. We will use these terms interchangeably. As we have seen, uncertainties about general economic conditions, such as GDP, interest rates, or inflation, are examples of systematic risks. These conditions affect nearly all panies to some degree. An unanticipated increase, or surprise, in inflation, for example, affects wages and the costs of supplies that panies buy, it affects the value of the assets that panies own, and it affects the prices at which panies sell their products. Forces such as these, to which all panies are susceptible, are the essence of systematic risk. In contrast, the announcement of an oil strike by a pany will primarily affect that pany and, perhaps, a few others (such as primary petitors and suppliers). It is unlikely to have much of an effect on the world oil market, however, or on the affairs of panies not in the oil business, so this is an unsystematic event. Systematic and unsystematic ponents of return The distinction between a systematic risk and an unsystematic risk is never really as exact as we make it out to be. Even the most narrow and peculiar bit of news about a pany ripples through the economy. This is true because every enterprise, no matter how tiny, is a part of economy. It’s like the tale of a kingdom that was lost because one horse lost a shoe. This is mostly hairsplitting, howeve