منابع اطلاعات، اخبار و شایعات در بازارهای مالی: نگاهی به بازار ارز

This article presents empirical findings on collective information processing in financial markets. Results are based on a questionnaire survey with 321 traders and 63 financial journalists from leading banks and financial news providers in the European foreign exchange market. Rating each other as the most important information source, foreign exchange traders and financial journalists are engaged in a circular pattern of market information processing, in which trading participants and financial news services form an interdependent relationship. Recent developments in technology have profoundly changed the nature of reporting and the role of news media in the foreign exchange market. Traders rate the speed of news and its anticipated impact on other market participants as more important than its perceived accuracy. These findings may help explain the role played by rumors in financial markets.

Neoclassical economic models of financial markets assume that participants make decisions on the basis of all available information and that they use this information fully and in an unbiased way. Based on the assumption of rational market participants, the efficient markets hypothesis postulates that prices always fully reflect the available information (Fama, 1970; Jensen, 1978). In financial markets, rational decision making and market behavior are assumed to be natural and therefore not in need of explanation (Cosmides & Tooby, 1994). Recent years, however, have seen the efficient market hypothesis challenged both theoretically and by a number of contradicting empirical observations (Shefrin, 2000; Shleifer, 2000). For example, Thaler (1992) contrasts the plethora of observable market “anomalies” to the rationality assumption, which supposes that market participants possess the magic ability to intuitively solve economic problems with which even economists struggle. In the foreign exchange market, a number of authors have observed that in contrast to the assumption of full and unbiased information processing, particularly in short-term movements of exchange rates, models based on economic fundamentals alone have not been successful (Flood & Taylor, 1996; Harvey, 1996; MacDonald & Taylor, 1992). For example, economic analysis of growth rates or of trade cannot predict most short-term exchange rate changes (Frankel & Froot, 1990), and such “rational” economic concepts as purchasing power parity are not seen as useful by foreign exchange traders themselves (Cheung & Chinn, 2001). The rational view proposed by neoclassical economics is also contradicted by Harvey (1996), who uses such phenomena as the existence of trading rules that reliably generate profits and the expectation biases evident in short-term exchange rate behavior surveys as evidence for the irrationality of market participants. In addition to these challenges to the efficient market theory, such market practitioners as the infamous speculator George Soros (1987, p. 29) have observed that supply and demand in financial markets are not independent givens, but that they instead contain “participants' expectations about events that are shaped by their own expectations”. Soros' theory of reflexivity stresses the interdependency between the market and market participants' views. Approaches to markets which consider first- and even higher order beliefs of other market participants' beliefs often refer to Keynes' (1936) metaphor of the market as beauty contest, which suggests that market processes require an understanding not only of market participants' beliefs and expectations, but also of market participants' assumptions about other market participants' beliefs and expectations (Allen, Morris, & Shin, 2002; Morris & Shin, 1998). How then is news and information processed in financial markets, and how do market participants decide on which information to base their trading decisions on? In the financial literature, a number of sophisticated attempts have been made to remedy the theory of information processing in financial markets. For example, Bikhchandani, Hirshleifer, and Welch (1992) examine the role of informational cascades in financial fads where it is optimal for the investor to simply follow the behavior of others. Also, Banerjee (1992) shows that optimizing decision rules may be characterized by market participants' herd behavior without using their own information. Moreover, in a consequential move away from the rationality postulate of economics, behavioral finance and financial market psychology emphasize that it is indispensable to consider psychological variables and processes when approaching the market (De Bondt & Thaler, 1994; Katona, 1980). These approaches question and expand the assumption that market participants are rational and that markets are efficient by considering human information processing features. In an effort to better understand the reality of financial markets, psychological and behavioral approaches shift the attention from modeling collective outcomes to observing and describing human information processing and decision making in the markets. After all, writes Maital (1982), markets “are arrangements where goods, money, and real and financial assets change hands. It is vital to remember that the hands are human and are attached to thinking, feeling heads and bodies”. Attitudes of market participants are one example of how psychologically informed empirical research may contribute to a better understanding of actual information processing in markets. Accordingly, attitudinal selectivity studies demonstrate that existing attitudes can bias human information processing (Biek, Wood, & Chaiken, 1996; Broemer, 1998; Eagly, 1998). They show that a variety of selective processes influence both availability and the use of information (Smid & Mulder, 1995). In the foreign exchange market traders often evaluate their “home” currency more positively, and traders' positive attitudes towards currencies correlate with their expectations of currency appreciation (Oberlechner, 2001a). Information circulating and interpreting dynamics of market participants then affect such collective market outcomes as exchange rates (Kirman, 1995). Another area which sheds new light on how information in the financial markets is actually processed is the examination of the role of news media and the relationship between news media and market participants. Financial news providers play a crucial role in the financial markets by disseminating information to the trading and investing decision makers. Despite their efforts to appear as impartial market observers, the news media play an important role in market processes, as the historical connection of the onset of speculative market bubbles to the introduction of newspapers shows (Shiller, 2000). Based on survey data from professional market participants, the present article aims at examining key questions in the collective dynamics of information processing in the foreign exchange market. These questions address how market participants collect market information, i.e., which information sources they use, and what kind of information they select as relevant for their decisions. Because of the critical role for market information processing played by news providers, financial journalists are examined as well. In particular, to examine how information is processed in the foreign exchange market, the present study addresses the following questions: 1. What are the most important market information sources of foreign exchange traders and of financial news journalists? 2. What are some of the recent trends in financial news reporting? In particular, how do financial journalists perceive the relationship between news providers and trading decision makers? 3. What information characteristics are important to foreign exchange traders? 4. How can these findings on information processing and financial news trends help explain rumors, a market phenomenon described by market practitioners as a regular occurrence in the foreign exchange market?

According to neoclassical economic theory, financial markets and trading decisions are based on a rational and unbiased processing of all available market information. Foreign exchange market participants' assessments of such important aspects of their information processing as their information sources, recent trends in financial news reporting, the changing relationship between financial news providers and trading decision makers, and the way market information is weighed, contradict this notion. Instead these assessments suggest that information processing in the market is selective and influenced by social dynamics between groups (Scharfstein & Stein, 1990; Shiller, 1989). The findings of our study may aid in explaining the role of rumors in the foreign exchange market. Our findings indicate that financial markets may be less about the actuality of economic facts than about how information is perceived and interpreted by market participants, and that technological advances have dramatically increased the speed and the amount of available market information. At the same time, these technologies have helped turn the present of the market into the past, causing market participants to shift their attention further away from the available market present towards possible market futures. Assisted by inherent features of collective market information processing and by the tendency to fulfill their psychological needs, market participants understand market rumors to indicate how these futures might look.