Crashing is seldom planned. Who knows what the gentle nudge will be this time. Maybe a war in the Middle East causing an oil shock (Iranian talks just broke down). Maybe a Katrina-type event hitting the right part of the US, causing an oil shock. Maybe QEx simply becoming old news, causing interest rates to rise (aka Fedheads losing control). Maybe an economic crisis elsewhere like China. In any case, it will be extremely fucking amusing to watch when it happens.