The limitations of technical analysis

In simple terms

This path has taught chart tools carefully: how each is built, what it measures and how it misleads. The final question is the obvious one: does any of it work? That is, can chart-based rules reliably earn more than simple alternatives after costs?

The honest answer is that the evidence is weak and mixed, that most short-term traders lose money, and that chart tools are more useful for describing and managing risk than for predicting prices.

The efficiency argument

The efficient market argument says that prices quickly reflect publicly available information. Past prices are the most public information of all. If a chart pattern reliably predicted gains, traders would buy earlier and earlier until the pattern disappeared. So, the argument goes, no publicly known price rule can reliably beat the market after costs.

Markets are not perfectly efficient: prices sometimes overreact, behavioural biases exist, and some participants are forced to trade for reasons unrelated to value. But markets are highly competitive. Many professional firms, with fast systems and low costs, search price data for patterns full-time. Any edge an individual finds on a free charting tool is likely to be small, already known, or illusory.

What research has found

Academic studies of technical trading rules over many decades and markets have produced mixed results. In general terms:

• Some effects have been documented, such as a tendency for shares that have risen strongly over several months to continue for a while, often called momentum, and short-term reversals over very short horizons. These effects are small, vary by market and period, and have weakened at times after becoming widely known.
• Many popular rules show little or no edge when tested fairly, out of sample and after costs.
• Early studies that found profits often did not include realistic costs, used data with biases, or tested many rules and reported the best, the problems described in the backtesting biases and overfitting lessons.

Research continues, and findings differ. But there is no body of evidence showing that ordinary chart patterns and indicators reliably beat simple investing after costs for individual traders.

"It works because everyone uses it"

A common defence is that technical analysis is self-fulfilling: if enough traders buy at a support level, the level holds. There is some truth in it. Clustered orders can make watched levels matter briefly, as the support and resistance lesson explains.

But self-fulfilment cannot make a signal reliably profitable for those who follow it. If everyone buys at the same level, prices rise before most of them can buy, and those who act fastest, usually professionals with the lowest costs, take most of the gain. Widely known signals are also exactly where others place orders to take advantage of the crowd, producing the stop runs and false breakouts described earlier.

What happens to traders

SEBI has studied how individual traders actually fared. Its study of intraday trading in the equity cash segment found that about 7 in 10 individual intraday traders made a net loss in 2022-23, and its study of equity futures and options found that 93% of individual traders made losses over 2021-22 to 2023-24. The investing compared with trading lesson discusses these findings. Costs, competition with professionals, and position sizes too large for the risks all play a part.

Sensible uses of chart tools

Chart tools are not useless. Used modestly, they help with:

• Describing price history accurately: trends, ranges, volatility.
• Judging liquidity and costs from volume and spreads.
• Managing risk: sizing positions with ATR, placing stops, planning exits, as the trading process module explains.
• Timing execution of decisions made for other reasons, for example avoiding buying on a day of extreme volatility.
• Spotting warning signs, such as unusual volume and price moves in promoted shares.

What they do not do reliably is predict where prices will go.

Why it matters

Technical analysis is sold widely, often with promises of income from trading. Understanding the evidence, and the experience of most traders, lets you keep the useful parts, description and risk management, while avoiding the expensive belief that charts can reliably predict prices.

Limitations

This lesson summarises a large, varied body of research in general terms; individual studies differ in methods and conclusions. Market conditions change, and effects may appear or disappear. The SEBI findings describe the periods studied.

Common mistakes

• Believing popularity proves effectiveness.
• Treating published past effects as permanent.
• Judging chart methods by memorable examples rather than fair tests.
• Ignoring costs and competition.

Try it yourself

1. Look back at the journal and tests you made in this path.
2. Note which of your hypotheses and rules held up after costs and on fresh data.
3. Compare your best result with simply holding an index fund over the same period.
4. Write down the uses of chart tools you will keep, and those you will drop.