Is technical analysis based on some underlying factors in the market or do they work simply because other people use them?
Technical analysis is based more on psychology than anything else. As an example, if an analyst estimates or believes that a stock is undervalued, or simply wants to re-balance their portfolio, then they will buy some amount, moving the price up. Others in the market see the upwards move as the start of an upwards trend, an indication that the stock is undervalued or perhaps even that an insider is trading ahead of better than expected data from the firm. They then buy the stock creating a self-fulfilling prophecy and pulling more traders in as they see an upward trend being confirmed. This is even more pronounced in a bear market as fear is an even stronger driver. When a trader sees a stock is falling they are more likely to jump to the conclusion that it is due to expected poor performance of the firm and that the firm and the economy are both in trouble and going down than to think that it is simply a retrenching or a large investor re-balancing etc. To quote Credit Suisse [1]  A chart is a mirror   of the mood of the crowd and not of the fundamental factors. Thus, technical analysis is the   analysis of human mass psychology. Therefore, it is also called behavioral finance. The underlying truth that makes technical analysis work is that people are predictably irrational, at least in the short run and tend to follow the same patterns of thought. references: [1] https://www.credit-suisse.com/pwp/pb/pb_research/technical_tutorial_de.pdf [2] http://www.amazon.com/The-Psychology-Technical-Analysis-Profiting/dp/1557385432 [3] CFA level 1 syllabus Technical Analysis assumes that the only relevant number(s) regarding a security is (are) price (and price momentum, price patterns, price harmonics, price trends, price aberrations, etc.). Technical is all based on price. Technical is not based on any of the fundamentals.  Technical Analysis is for traders (speculators) not for long term investors. A long term investor is more concerned with the dividend payment history and such similar data as he makes his money from the dividend payments not from the changes in price (because he buys and holds, not buy low sell high). "Both explanations are partly true. There are many investors who do not want to sell an asset at a loss.  This causes ""resistance"" at prices where large amounts of the asset were previously traded by such investors.  It also explains why a ""break-through"" of such a ""resistance"" is often associated with a substantial ""move"" in price. There are also many investors who have ""stop-loss"" or ""trailing stop-loss"" ""limit orders"" in effect.  These investors will automatically sell out of a long position (or buy out of a short position) if the price drops (or rises) by a certain percentage (typically 8% - 10%). There are periods of time when money is flowing into an asset or asset class.  This could be due to a large investor trying to quietly purchase the asset in a way that avoids raising the price earlier than necessary.  Or perhaps a large investor is dollar-cost-averaging.  Or perhaps a legal mandate for a category of investors has changed, and they need to rebalance their portfolios.  This rebalancing is likely to take place over time.  Or perhaps there is a fad where many small investors (at various times) decide to increase (or decrease) their stake in an asset class.  Or perhaps (for demographic reasons) the number of investors in a particular situation is increasing, so there are more investors who want to make particular investments.  All of these phenomena can be summarized by the word ""momentum"". Traders who use technical analysis (including most day traders and algorithmic speculators) are aware of these phenomena.  They are therefore more likely to purchase (or sell, or short) an asset shortly after one of their ""buy signals"" or ""sell signals"" is triggered.  This reinforces the phenomena. There are also poorly-understood long-term cycles that affect business fundamentals and/or the politics that constrain business activity.  For example: Note that even if the markets really were a random walk, it would still be profitable (and risk-reducing) to perform dollar-cost-averaging when buying into a position, and also perform averaging when selling out of a position.  But this means that recent investor behavior can be used to predict the near-future behavior of investors, which justifies technical analysis."
It does when you argue that a single factor is causing the price chart to move a certain way.  If they start to think it's perhaps more complicated than that, then yes, it breaks down quickly, which was precisely my point. In fact markets are not efficient and participants are not rational. That is why we have booms and busts in markets. Emotions and psychology play a role when investors and/or traders make decisions, sometimes causing them to behave in unpredictable or irrational ways. That is why stocks can be undervalued or overvalued compared to their true value.  Also, different market participants may put a different true value on a stock (depending on their methods of analysis and the information they use to base their analysis on). This is why there are always many opportunities to profit (or lose your money) in liquid markets. Doing your research, homework, or analysis can be related to fundamental analysis, technical analysis, or a combination of the two. For example, you could use fundamental analysis to determine what to buy and then use technical analysis to determine when to buy. To me, doing your homework means to get yourself educated, to have a plan, to do your analysis (both FA and TA), to invest or trade according to your plan and to have a risk management strategy in place. Most people are too lazy to do their homework so will pay someone else to do it for them or they will just speculate (on the latest hot tip) and lose most of their money. "Below is just a little information on this topic from my small unique book ""The small stock trader"":  The most significant non-company-specific factor affecting stock price is the market sentiment, while the most significant company-specific factor is the earning power of the company. Perhaps it would be safe to say that technical analysis is more related to psychology/emotions, while fundamental analysis is more related to reason – that is why it is said that fundamental analysis tells you what to trade and technical analysis tells you when to trade. Thus, many stock traders use technical analysis as a timing tool for their entry and exit points. Technical analysis is more suitable for short-term trading and works best with large caps, for stock prices of large caps are more correlated with the general market, while small caps are more affected by company-specific news and speculation…: Perhaps small stock traders should not waste a lot of time on fundamental analysis; avoid overanalyzing the financial position, market position, and management of the focus companies. It is difficult to make wise trading decisions based only on fundamental analysis (company-specific news accounts for only about 25 percent of stock price fluctuations). There are only a few important figures and ratios to look at, such as: perhaps also: Furthermore, single ratios and figures do not tell much, so it is wise to use a few ratios and figures in combination. You should look at their trends and also compare them with the company’s main competitors and the industry average. Preferably, you want to see trend improvements in these above-mentioned figures and ratios, or at least some stability when the times are tough. Despite all the exotic names found in technical analysis, simply put, it is the study of supply and demand for the stock, in order to predict and follow the trend. Many stock traders claim stock price just represents the current supply and demand for that stock and moves to the greater side of the forces of supply and demand.  If you focus on a few simple small caps, perhaps you should just use the basic principles of technical analysis, such as:  I have no doubt that there are different ways to make money in the stock market. Some may succeed purely on the basis of technical analysis, some purely due to fundamental analysis, and others from a combination of these two like most of the great stock traders have done (Jesse Livermore, Bernard Baruch, Gerald Loeb, Nicolas Darvas, William O’Neil, and Steven Cohen). It is just a matter of finding out what best fits your personality.  I hope the above little information from my small unique book was a little helpful! Mika (author of ""The small stock trader"")" Here are some significant factors affect the company stock price performance: Usually, profitability is known to the public through the financial statements; it won't be 100% accurate and people would also trade the stock with the price not matching to the true value of the firm. Still there are dozens of other various reasons exist. People are just not behaving as rational as what the textbook describes when they are trading and investing. all of these examples are great if you actually believe in fundamentals, but who believes in fundamentals alone any more? Stock prices are driven by earnings, news, and public perception. For instance, a pharma company named Eyetech has their new macular degeneration drug approved by the FDA, and yet their stock price plummeted. Typically when a small pharma company gets a drug approved, it's off to the races. But, Genetech came out said their macular degeneration drug was going to be far more effective, and that they were well on track for approval. I recall the name Martin Pring. As my fundamental analysis book from grad school was the work of Graham and Dodd titled Security Analysis, Pring was the author of the books I read on technical analysis. If you've not read his work, your education has a ways to go before you hit the tools. My view is that hedge funds and high-frequency traders tend to create this correlation because they're making directional bets on individual stocks, grouped as a whole, and then share these ideas with so many other funds (who, in turn, do the same thing).  I think Beta and inflated share prices are related to this effect, but are not the cause of this effect. "For some studies on why investors make the decisions they do, check out  For a more readable, though less rigorous, look at it, also consider Kahneman's recent book, ""Thinking, Fast and Slow"", which includes the two companion papers written with Tversky on prospect theory. In certain segments (mostly trading) of the investing industry, it is true that something like 90% of investors lose money. But only in certain narrow segments (and most folks would rightly want traders to be counted as a separate beast than an 'investor').  In most segments, it's not true that most investors lose money, but it still is true that most investors exhibit consistent biases that allow for mispricing. I think that understanding the heuristics and biases approach to economics is critical, both because it helps you understand why there are inefficiencies, and also because it helps you understand that quantitative, principled investing is not voodoo black magic; it's simply applying mathematics for the normative part and experimental observations for the descriptive part to yield a business strategy, much like any other way of making money." There's a whole industry devoted to this.  Professionals use Bloomberg terminals. High Frequency Traders have computers read news feeds for them. Amateurs use trading consoles (like Thinkorswim) to get headlines quickly on stocks. "Stock price is determined by the buyers and sellers, correct? Correct! ""Everything is worth what its purchaser will pay for it""-Publius Syrus What causes people to buy or sell? Is it news? earnings? stock analysis and techniques? All of these things influence investors' perception of how much a stock is worth. If AMZN makes a lot of money one quarter, then the price might go up. But maybe public perception of AMZN changes because of a large scandal. This could cause the share price to decline even with the favorable earnings report. Why do these 'good' or 'bad' news make people want to buy/sell a stock? People invest to make money. If it looks like a company is going to take a turn for the worst, people will sell. If it looks like the company has a bright, cash-laden future in front of them, people will buy. News is one of the many factors people use to determine how well a company will do. Theoretically could a bunch of people short AMZN and drive down the price regardless of how well it is doing? Say investors wanted to boycott AMZN in order to drive down the cost and get some cheap shares. This is pretty silly, but say for the sake of the argument that everyone who owned AMZN decided to sell their shares and no other investor was willing to buy the shares for less than $0.01, then AMZN shares would be ""worth"" $0.01 in that aspect. That is extremely unlikely to happen, though, for two reasons:" The strategy has intrinsic value, which may or may not be obstructed in practice by details mentioned in other answers (tax and other overheads, regulation, risk). John Bensin says that as a general principle, if a simple technical analysis is good then someone will have implemented it before you. That's fair, but we can do better than an existence proof for this particular case, we can point to who is doing approximately this. Market makers are already doing this with different numbers. They quote a buy price and a sell price on the same stock, so they are already buying low and selling high with a small margin. If your strategy works in practice, that means you can make low-risk money from short-term volatility that they're missing out on, by setting your margin at approximately the daily price variation instead of the current bid-offer spread. But market makers choose their own bid-offer spread, and they choose it because they think it's the best margin to make low-risk money in the long run. So you'd be relying that: Bloomberg Professional seems to be very popular. It provides any kind of data you can imagine. Analysis is a subjective interpretation of the data. No, and using a 37 year old formula in finance that is as simple as: should make it obvious technical analysis is more of a game for retail traders than investment advice. When it comes to currencies, there are a myriad of macroeconomic occurrences that do not follow a predictable timescale. Using indicators like RSI on any time frame will not magically illuminate broad human psychology and give you an edge. It is theoretically possible for a single public stock's price to be driven by a range of technical traders who all buy at RSI 30 and sell at RSI 70, after becoming a favorite stock on social media, but it is infinitely more likely for all market participants to have completely different goals. As you point out, the moving average is just MA(k)t = (Pt-1 + … + Pt-k )/k and is applied in technical analysis (TA) to smooth out volatile (noise) price action. If it has any logic to it, you might want to think in terms of return series (Pt - Pt-1 / Pt-1) and you could hypothesize that prices are in fact predictable and will oscillate below and above a running moving average.  Below is a link to a study on MA trading rules, published in the Journal of Finance, with the conclusion of predictive power and abnormal returns from such strategies. As with any decision made upon historical arguments, one should be aware of structural changes and or data mining.  Simple  technical trading rules and the stochastic properties of stock  returns Brock, W., J. Lakonishok and B. Le Baron, 1992, Simple technical trading rules and the stochastic properties of stock returns, Journal of Finance, 47, 1731-64. MA rules betterthan chance in US stock market, 1897-1986 I don't know whether you are new to TA or not, but a great commercial site, with plenty of computer-generated signals is FinViz. Bank accounts?  It is worse than that.  People are afraid to invest in bank accounts. Did you see the bit when German government bonds hit a negative interest rate recently? (As in you buy a bond and in five years time the government promises to give nearly all of it back)