Imagine trying to predict the weather. You could study atmospheric science, pressure systems, and global climate data. Or, you could look out the window, see dark clouds gathering, and guess it's probably going to rain. Technical analysis is a lot like looking at the clouds.

It's a method of forecasting the direction of prices by studying past market data, mainly price and volume. Instead of digging into a company's financial health or the economy, technical analysts focus on the patterns and trends visible on a price chart. They believe the chart itself tells the story of supply and demand, and contains all the information needed to make a trading decision.

Technical analysis rests on three core beliefs. Understanding them is key to understanding the entire approach.

This is the cornerstone idea. Technical analysts assume that at any given moment, an asset's price reflects everything that could possibly affect it. This includes news events, earnings reports, economic forecasts, and investor sentiment. All this information is baked into the price you see on the screen.

Because of this, they argue there's no need to analyze those external factors separately. The only thing worth studying is the price action itself, as it's the final product of all forces acting on the market.

Once a trend is in motion, it's more likely to continue than to reverse. Think of it like inertia. An object in motion stays in motion. Technical analysts work to identify the direction of the current trend—whether it's up, down, or sideways—and ride it for as long as it lasts. The old trading adage, "the trend is your friend," comes directly from this principle.

An uptrend is marked by a series of higher highs and higher lows. A downtrend has lower lows and lower highs. A sideways trend, or range, moves back and forth without a clear direction.

This final pillar is based on human psychology. The way people react to price movements—with fear, greed, and hope—tends to be consistent over time. Because these reactions are predictable, certain chart patterns emerge again and again.

Technical analysts study these historical patterns to find clues about what might happen in the future. If a specific pattern led to a price increase 80% of the time in the past, an analyst seeing that same pattern today might bet on the price going up.

So, how does this differ from the other main school of thought, fundamental analysis?

Fundamental analysis is like being a detective for a company. You investigate its financial statements, management team, competitive advantages, and the overall health of its industry and the economy. The goal is to determine a company's intrinsic value—what it's really worth. If the market price is below that intrinsic value, a fundamental analyst sees a buying opportunity.

Technical analysis, on the other hand, isn't concerned with intrinsic value. A technical analyst, or "technician," believes that the company's value is whatever the market is willing to pay for it right now. They look at the chart to determine the market's mood and direction.

Neither approach is necessarily better than the other; they're just different tools for different jobs. Some investors use only one, while many use a combination of both to get a fuller picture of the market.