We know that the birth of an uptrend comes from the first upward reversal pattern, and the generation of an upward reversal pattern requires the first generation of two troughs and the latter

Sub-reversal buy point

We know that the birth of an uptrend comes from the first upward reversal pattern, and the production of the upward reversal pattern first requires the production of two troughs, and the subsequent troughs must be higher than the previous troughs. That is to say, when the second trough is generated, as long as this trough low is higher than the low of the previous trough, the market has the possibility of producing a reversal pattern, producing a reversal pattern, that is, there is a possibility of further evolution into an uptrend, if the inference holds true, then buying at the second trough low is theoretically better than confirming the buy point. Since it is unknown whether the second trough low can evolve into a reversal pattern and then an uptrend, we define this buy point as a sub-reversal buy point. Subversion means that it is about to be reversed but has not yet been reversed.