Speculative Bubble

What is a speculative bubble?

A speculative bubble, also known as an economic bubble, is a rapid run-up in prices caused by excessive buying that is unrelated to any of the basic, underlying factors affecting the supply or demand for a commodity or other asset. Speculative bubbles are usually associated with a "bandwagon" effect in which speculators rush to buy the commodity (in the case of futures, "to take positions") before the price trend ends, and an even greater rush to sell the commodity (unwind positions) when prices reverse. (Source: CFTC)

An economic bubble (sometimes referred to as a "market bubble", a "financial bubble", or a "speculative mania") refers to a market condition in which the prices of commodities or asset classes increase to absurd or unsustainable levels (that no longer reflect utility of usage and purchasing power). It occurs when speculation in the underlying asset causes the price to increase, thus encouraging even more speculation. The bubble is usually followed by a sudden drop in prices, known as a crash or a bubble burst. Both the boom and the bust phases of the bubble are examples of a positive feedback mechanism, in contrast to the negative feedback mechanism that determines the equilibrium price under normal market circumstances. Prices in an economic bubble can fluctuate chaotically, and become impossible to predict from supply and demand alone.

Economic bubbles are generally considered to have a negative impact on the economy because they cause misallocation of resources into non-optimal uses. In addition, the crash which usually follows an economic bubble can destroy a large amount of wealth and cause continuing economic malaise. A protracted period of low risk premiums can simply prolong the downturn in asset price deflation as was the case of the Great Depression in the 1930s for much of the world and the 1990s for Japan. Not only can the aftermath of a crash devastate the economy of a nation, but its effects can also reverberate beyond its borders.

Another important aspect of economic bubbles is their impact on spending habits. Market participants with overvalued assets tend to spend more because they "feel" richer (the Wealth Effect). Many observers quote the housing market in the United Kingdom, Australia, Spain and parts of the United States in recent times, as an example of this effect. When the bubble inevitably bursts, those who hold on to these overvalued assets usually experience a feeling of poorness and tend to cut discretionary spending at the same time, hindering economic growth or, worse, exacerbating the economic slowdown. Therefore, it is imperative for the central bank to keep its eyes on asset price appreciation and promptly take preemptive measures to curb high level of speculative activity in financial assets.

When the bubble occurs in equity markets, it is called a stock market bubble. It is usually very difficult to differentiate a stock market bubble from an ordinary bull market except in hindsight. (Source: Wikipedia)

Random Walk Theory

What is Random Walk Theory and what are its implications for financial markets?

"Random Walk" is an economic theory that market price movements move randomly. This assumes an efficient market. The theory also assumes that new information comes to the market randomly. Together, the two assumptions imply that market prices move randomly as new information is incorporated into market prices. The theory implies that the best predictor of future prices is the current price, and that past prices are not a reliable indicator of future prices. If the random walk theory is correct, Technical Analysis cannot work. (Source: CFTC)

The random walk hypothesis is a financial theory stating that stock market prices evolve according to a random walk and thus the prices of the stock market cannot be predicted. It has been described as 'jibing' with the efficient market hypothesis. Investors, economists, and other financial behaviorists have historically given into the random walk hypothesis. They have run several tests and still believe that stock prices are completely random because of the efficiency of the market.

The term was popularized by the 1973 book, "A Random Walk Down Wall Street", by Burton Malkiel, currently a Professor of Economics and Finance at Princeton University.

Burton G. Malkiel, an economist professor at Princeton University and writer of A Random Walk Down Wall Street, did a test where his students were given a hypothetical stock that was initially worth fifty dollars. The closing stock price for each day was determined by a coin flip. If the result was heads the price would close a half point higher, and subsequently if the result was tails, it would close a half point lower. Each time there was a fifty-fifty chance of the price closing higher or lower than the previous day. There were cycles or trends determined from the tests. Malkiel then took the results in a chart and graph form to a chartist (a person who “seeks to predict future movements by seeking to interpret past patterns on the assumption that ‘history tends to repeat itself’”) (Keane 11). The chartist told Malkiel that they needed to immediately buy the stock. When Malkiel told him it was based purely on flipping a coin, the chartist was very unhappy. This indicates that the market and stocks could be just as random as flipping a coin.

The random walk hypothesis was also applied to NBA basketball. Psychologists did a detailed study of every shot the Philadelphia 76ers made over one and one-half seasons of basketball. The psychologists found no positive correlation between the previous shots and the outcomes of the shots afterwards. Economists and believers in the random walk hypothesis apply this to the stock market. The actual lack of correlation of past and present can be easily seen. If a stock goes up one day, no stock market participant can accurately predict that it will rise again the next. Just as a basketball player with the “hot hand” can miss his or her next shot, the stock that seems to be on the rise can fall at any time, making it completely random.

There are other economists, professors, and investors that believe that the market is predictable to some degree. The people believe that there are trends and incremental changes in the prices and when looking at them, one can determine whether the stock is on the rise or fall. There have been key studies done by economists and even a book written by two professors of economics that try to prove the random walk hypothesis wrong.

Martin Weber, a leading researcher in behavioral finance, has done many tests and studies on finding trends in the stock market. In one of his key studies, he observed the stock market for ten years. Over those ten years, he looked at the market prices and looked for any kind of trends. He found that stocks with high price increases in the first five years tended to become under-performers in the following five years. Weber and other believers in the non-random walk hypothesis cite this as a key contributor and contradictor to the random walk hypothesis.

Another test that Weber ran that contradicts the random walk hypothesis was finding stocks that have had an upward revision for earnings outperform other stocks in the forthcoming six months. With this knowledge, investors can have an edge in predicting what stocks to pull out of the market and what stocks, the stocks with the upward revision, to leave in. Martin Weber’s studies detract from the random walk hypothesis, because according to Weber there are trends and other tips to predicting the stock market. Professors Andrew W. Lo and Al. Craig MacKinlay professors of Finance at Sloan School of Management and the University of Pennsylvania, respectively, have also tried to prove theory wrong. They wrote the book A Non-Random Walk Down Wall Street, that goes through a number of tests and studies that try to prove that there are trends in the stock market and they are somewhat predictable. They argue that the random walk does not exist and that even the casual observer can look at the many stock and index charts generated over the years and see the trends. If the market were random, it is argued, there would never be the many long rises and declines so clearly evident in charts. Subscribers to the random walk hypothesis counter argue that past performance cannot be indicative of future performance in a semi-strong market economy. (Source: Wikipedia)

Efficient Market Hypothesis

What is the Efficient Market Hypothesis?

In economic theory, an efficient market is one in which market prices adjust rapidly to reflect new information. The degree to which the market is efficient depends on the quality of information reflected in market prices. In an efficient market, profitable arbitrage opportunities do not exist and traders cannot expect to consistently outperform the market unless they have lower-cost access to information that is reflected in market prices or unless they have access to information before it is reflected in market prices. (Source: CFTC)

In finance, the efficient market hypothesis (EMH) asserts that financial markets are "efficient", or that prices on traded assets, e.g. stocks, bonds, or property, already reflect all known information and therefore are unbiased in the sense that they reflect the collective beliefs of all investors about future prospects. Professor Eugene Fama at the University of Chicago Graduate School of Business developed EMH as an academic concept of study through his published Ph.D. thesis in the early 1960s at the same school.

The efficient market hypothesis states that it is not possible to consistently outperform the market — appropriately adjusted for risk — by using any information that the market already knows, except through luck. Information or news in the EMH is defined as anything that may affect stock prices that is unknowable in the present and thus appears randomly in the future. This random information will be the cause of future stock price changes. (Source: Wikipedia)