First, market behavior reflects all information

First, market behavior reflects all information. This means that the price itself is a perfect analytical tool, assuming that the market price already contains all the relevant information.

Second, prices follow a trend. This is the assumption that prices tend to move in a certain direction, and this trend is likely to continue.

Therefore, technology analysts want to predict future price movements through past price patterns.

Third, history repeats itself. By believing that past price patterns and market behaviors are likely to repeat, the premise is that the future can be predicted through historical data.

underlying family and investment philosophy

Hydeuljeok Market hypothesis

Efficient Market Hypothesis.

It is a hypothesis that prices quickly reflect "all available information" about a product and therefore cannot exceed market returns in the long run using that information. It is known as a theory first advocated by Eugene Pharma, who later won the Nobel Prize in Economics.
2. Details [edits]
Price fluctuations cannot be predicted because rational expectations are quickly reflected in prices. Originally, it was about the stock market, but similar markets such as bonds and foreign exchange were analyzed.

Based on the criteria of "all available information," there are three types: weak, quasi-rigid, and steel, and most empirical analyses deal with weak or quasi-rigid hypotheses.
• Weak form
Market transaction data (past stock price, volume, total short selling, etc.) alone cannot exceed market returns in the long run.
• Semi-strong form
In addition to market transaction data, disclosure information related to the company's outlook (basic data on product lines, capabilities of management, balance sheet composition, patents held, expected returns, accounting practices, etc.) cannot exceed market returns in the long run.
• Strong form
Even if non-public information (insider transactions, etc.) is used in addition to public information, the stock price has already reflected all the information in the outlook, so it cannot exceed the market rate of return in the long run.
3. an empirical study [editing]
First of all, there are studies showing that the correlation between the stock market price in the previous year and the price in the current year is close to zero, and many studies show that the weak type is established in large part.

On the other hand, there are many results that support the efficient market hypothesis, for example, in 1988, the WSJ confronted four expert analysts with a portfolio formed by blindfolded monkeys throwing darts. The results of the 14-year experiment were a crushing defeat for analysts. Monkeys returned 2.3%, while analysts had a 1.2% return. And in the long run, the majority of investment experts performed worse than index funds, and the number of experts who recorded higher returns than index funds also did not significantly refute the efficient market hypothesis statistically. Warren Buffett, a famous investor, also made a bet similar to a hedge fund manager after the 2008 financial crisis[1], and a 10-year comparison of yields showed that index funds won.[2]
4. a counterargument [editing]
It is a hypothesis that has been challenged both empirically and practically. If you leap from 'the market is efficient' to 'the market is efficient', the wording is similar, but the approach is the opposite.

Behavioral financiers such as Robert Schiller and Steve Thaler have proposed inefficient market hypotheses against efficient market hypotheses. Like behavioral economics, people are often unreasonable, and even if people are reasonable, they underestimate or overreact because the opportunities for arbitrage trading[3] may be limited in reality and tend to generalize some cases statistically. [4] The January effect,[5] empirical analyses based on specific investment strategies[6] are the counter examples of quasi-rigid and rigid EMH. [7] People like Warren Buffett are also the counter examples of quasi-rigid and rigid.

Although there are no positive empirical research results today for EMH itself, Somers statistically explained the interpretation that the power of EMH is weak. [8][9] To be more precise, the amount of data is insufficient to verify the efficient market hypothesis in research based on past market information accumulated to date.

In addition, EMH was criticized for not being able to explain the huge crisis such as the 2008 crisis. Among them, the emergence of EMH has slowed the perception of crisis, which is not logically and empirically valid. With or without EMH, there have already been several financial crises in the world, and Alan Greenspan has also acknowledged the possibility of irrational greed. According to EMH, the current stock price is the result of completely reflecting all public information, and it is another matter of whether a bubble can be predicted with private information.
4.1. Shelf Young [edited]
In the stock market, based on the quasi-rigid theory of the efficient market hypothesis, all current information is reflected in the stock price, and the word shelf-young expresses that the price at that point is the most efficient price.

However, it differs slightly from the content of the efficient market hypothesis, except for the latter part of the hypothesis, which is slightly twisted as "price reflects all available information about the product quickly, and all information disclosed to market participants is shelf-aged in the market."

According to the shelf management theory, institutional investors in the stock market already expect sales and net profits in six months to a year and reflect them as stock prices, so the current stock price is the most efficient price determined by institutional investors.

At first glance, it is true, but it cannot be ignored that shelf-young is inaccurate just by looking at the institutional investor consensus every time, so even though the theory is actually wrong, shelf-young theory is often sprayed with the word "shelf reflection" to justify when stock prices are too pumped or too low.

In practice, stock prices change depending on the investor's psychological state, so they can never be fully screened, and even if it's already been screened, the current investors'