So if the stocks in your IRA are performing well, why are you pessimistic?
I think the best thing is to decide a target AA, get to it and stick to it until your circumstances change such that the target AA no longer makes sense for you.
If I look back over the past 30 years, all of the investing mistakes/missed opportunities that I have made are the result of not following my AA (or in 2008 having the courage to buy stocks when my AA was telling me to). Cost me a bunch.
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The nice thing about AA is it disciplines me to buy lower and sell higher. It beats following my gut instincts.