The three tenets of technical analyses are:
Market action discounts everything
Anything that can possibly affect the price is reflected in the price of the market. Therefore all that is required is the study of price action.
Prices move in trends
This is the market equivalent of Newton’s first law: a trend in motion is more likely to continue than to reverse.
History repeats itself
Patterns that worked well in the past will continue to work well in the future.