The “butterfly effect” is a term from a pioneer of chaos theory, Edward Lorenz; his 1972 presentation Predictability: Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas? describes the idea that a tiny event can start a chain reaction and have large and wide-reaching effects. We know the big changes and events the markets face in the second half of 2013: the potential end of the Federal Reserve’s (Fed) bond-buying program, the need for Congress to...