One of the more notable aspects of the paroxysms that have shaken markets around the world in recent weeks is something they have lacked: reams of commentary on the risk-on, risk-off nature of trading.

The shift in market terminology underscores deeper changes in investors' thinking. That is of particular note given sudden uncertainty around the direction of stocks and worries that the bond market may soon approach a turning point where yields rise even more sharply than they have in recent weeks.