First of all, we should find two high points (or low points) with different heights and a certain distance, and tentatively draw a straight line for falling (or rising) from them.
If the rising support line is drawn, the price should be at a certain distance from the second low. If it is close to or exceeds the previous resistance level, the trend line can be identified, while the situation of drawing a falling resistance line is the opposite. The appearance of the third low point (or the third high point) is the verification of the effectiveness of the trend line.
The speed of price change may be accelerated or slowed down, and the range may be expanded or reduced. In some cases, the trend line should be adjusted accordingly, so that the trend line can adapt to the current price changes as much as possible.
Fan map. When the trend line is at the same origin and different slopes are adjusted to keep the original trend line, a fan chart composed of multiple support lines (or resistance lines) will be formed.
The rising resistance level of the two-line chart in the same direction can also be connected into a rising straight line, which is called a pipeline line, and the falling support level can also be connected into a pipeline line. Pipeline line and basic trend line can form several price forms with special significance.
Triangular graph, that is, reverse double-line graph. Draw an upward trend line and a downward trend line on the stock price chart at the same time, and these two trend lines will construct a basic price pattern: triangle chart.