How about learning stock trading and going to teacher Du's class? Is it reliable?

Reliable. Du's central theory and three daily limit tactics are to strictly define the rise and fall of the stock price, then draw the central point, and judge whether the current trend is opposite by comparing the trend before the central point and the trend after the central point, thus forming accurate 1, 2, 3 trading points, helping investors to capture the current buying point in time and accurately.