$AST SpaceMobile(ASTS.US) is the stock that has lost me the most money since I started trading US stocks. I didn't buy more when it was low earlier, and later I violated my trading principles by buying too much. To put it bluntly, my mindset was ruined by greed, and there were too many subjective factors. At that time, I basically gave back most of this year's profits. Later, I adjusted my mindset in time and switched back to the M7 stocks I'm familiar with, and quickly recovered my losses. This experience was very tough, but I also learned a lot. Experience is the best teacher.