Star Theory is truly an interesting subject. If you are a serious trader or investor, I just realized that this principle dates back over 100 years, yet it remains a fundamental basis of technical analysis to this day.

As you know, the Star Theory originated from an article by Charles H. Dow in The Wall Street Journal and was later developed by William Peter Hamilton in the early 20th century. Importantly, this theory may seem simple, but it is actually very profound.

What I like about Dow Theory is that it compares stock price movements to ocean waves. When the market is up (Uptrend), new highs are higher than previous highs, and new lows are higher than previous lows—called Higher Highs and Higher Lows. Conversely, when the market is down (Downtrend), it forms Lower Highs and Lower Lows. Not too difficult, right?

Dow Theory divides trends into three types: the Primary Trend, which lasts from 200 days up to sometimes 4 years; the Intermediate Trend, lasting about 3 weeks to 3 months; and the Minor Trend, which lasts no more than 3 weeks. Knowing which trend we are in helps us plan our trades much better.

Another key principle of Dow Theory is that the market has already absorbed all information—whether news, earnings forecasts, or other factors—all reflected in the price. Trading volume (Volume) is also important. In an uptrend, volume should increase, confirming that the trend is strong.

What I observe is that Dow Theory helps identify three critical phases. The first is Accumulation, where prices are still low, and value investors are accumulating. The second is Public Participation, where prices clearly rise, and volume increases—this is a good speculative phase. The last is Distribution, where prices soar, good news is abundant, small investors buy in, while large investors start to exit. This phase is high risk.

Patterns like Double Bottom and Double Top are also good signals for trend reversal. Double Bottom (W shape) indicates a market shifting from downtrend to uptrend. Double Top (M shape) indicates the opposite—an uptrend about to reverse downward.

The advantage of Dow Theory is that it has a clear foundation, is widely applicable, and effectively indicates market direction. It doesn’t rely on sometimes unstable economic figures. However, a downside is that it can be somewhat lagging; waiting for confirmation from the market might cause you to miss some opportunities because prices move quickly.

If you trade CFDs (Contracts for Difference), Dow Theory is very suitable because you can trade both directions—buy in an uptrend and sell in a downtrend. When you analyze based on Dow Theory, understanding the current trend and the likely direction of prices, your trading plans become much more disciplined.

In summary, Dow Theory is a powerful tool that remains relevant today. If you are serious about trading, you should spend time practicing and deeply understanding it, because a solid foundation will help you make better decisions in the long run.