DONCASTER, UK--Look, we all know to refrain from any bold pronouncements in such an uncertain world. But the same market that was last year first to be broadsided by the pandemic has now made consecutive statements: first one of cautious optimism and now, remarkably, one of record-breaking confidence. For if we left Newmarket last week reminding ourselves that a single swallow does not a summer make, then flight after flight seemed to fill the air at the Goffs UK Breeze-Up Sale. Whatever the ups and downs that inevitably still await,...