However if at years end stocks are now considered 10 % over valued by those same metrics and your stock allocation is now at 55 % because of the returns then rather than adjusting back down to 50 % perhaps now you adjust
your reasonable allocation percentage down to 45 % to reflect to over-valuation that is inherent in the current valuation of the stock market.
Not exact matches
A lot of academics have analyzed total market returns based on indices and done Monte Carlo simulations of portfolios with various asset
allocations, and have come up with
percentages that you can have
reasonable statistical confidence of being safe.
When valuations are in the
reasonable range (i.e., whenever P / E10 is less than 20), the optimal stock
allocation is almost always 80 %, the largest
percentage that I allow.