What is technical analysis?
A critical look at what technical analysis is, how observation differs from interpretation, the categories of tools, and its biggest trap — confirmation bias.
Technical analysis (TA) studies past price and volume to make probability-based inferences about likely future moves. Its core assumption is that price reflects information and that behavioural patterns can repeat. TA produces probabilities, not certainties.
Why it matters
Someone who treats TA as “reading hidden signals on a chart” tends to look for and confirm their own expectation. The real value of TA is helping you tie decisions to observable, repeatable conditions — not being a magic forecasting tool.
Evidence ladder: from weak to strong
- A single indicator
The weakest evidence; misleading on its own.
- Price + context
Reading level and trend together adds meaning.
- Several independent signals
Confidence rises when different sources agree.
- A rule tested on history
The strongest evidence: a defined, tested, measured rule.
Separate observation from interpretation
Observation is objective: “Price broke its 30-day high.” Interpretation is subjective: “So it will go up.” A good analyst does not blur the two; they record the observation, mark the interpretation as a probability, and define in advance what would prove them wrong.
Tool categories
| What it measures | Its limit | |
|---|---|---|
| Trend tools | Whether direction persists | Misleads in a sideways market |
| Momentum oscillators | The speed of a move | Signals early in a strong trend |
| Volume | Participation behind a move | Does not give direction alone |
| Levels | Zones where supply/demand cluster | A zone, not an exact line |
The most common mistake is confirmation bias: deciding on a direction and then seeing only the signals that support it. The antidote is to answer “under what condition is this idea wrong?” in advance.
TA cannot know the future, cannot foresee news shocks, and the same chart can be read differently by different people. To become reliable, it must turn into defined, testable rules rather than interpretation.
No technical pattern guarantees a gain; past behaviour may not repeat. TA is not sufficient on its own when it is not used together with risk management.
Once you can separate observation from interpretation, start with the most concrete observations: trend, support, and resistance. Move on to price action.