Last year, an ongoing bull run in the North American bloodstock market carried the juvenile sector to a historic breakthrough. For the first time, aggregate turnover broke the $200 million barrier. The momentum felt so giddy that the next milestone, with the mean cost of a 2-year-old standing at $95,807, promised to be a six-figure average. No market, of course, can sustain perennial growth. Capitalism requires recession to regenerate value. While these cycles will ideally be mild, this particular market is always especially exposed to any incipient weakness. Very often,...