Bull markets end with a sudden (may last for weeks or days) rush of "irrational exuberance" which everyone "riding the bull" will experience. (the last great "Bull" run in gold ended with a 40% rise in the bullion price in the last two weeks!)
Until you feel the "rush," its buy and hold!
The toughest thing you'll ever do as an investor is sell into the "rush!"
Be prepared! (nobody can time it exactly, but its a comin')
RUF