BYD ( OTCPK:BYDDY ) has been on the retreat, with stock prices down sharply over the past few months. I last recommended BYD in May, and shares are down about 17% since then. BYD is, admittedly, one of my worst-performing buy picks, but I stillMarkets rise and fall, booms come and go, and the world keeps ticking. Ultimately, I believe observing megatrends, as difficult as they can be to spot, let alone fully comprehend, can yield insights into the advance of human society, which in turn could pave the way f ...