Don't call it a "selloff" yet. After two straight weekly declines and losses in eight of the last 10 sessions, the S&P remains just ~3% from the highs, a testament to all manner of dynamics, from the esoteric to the obvious. One thing that's become clear enough is that people know when the dips are coming. Or, wait. Scratch that. Market participants know when the door is about to open to a wider distribution of outcomes, and that may be encouraging some folks to front-run potential index "