I like an idea Stansberry had on one of his podcasts. He calls it "allocate to value" which means buy whatever is the best value at that time. You could be in 90% stocks today then 90% in bonds next year. Things go in cycles so there's always something that is overpriced and something that is cheap. I'll use today as the example. Should you buy stocks today? I would say no. The market is at all time highs, people have record levels of margin debt (again), the Shiller PE is something ridiculous like 26, sub-prime lending is a problem (again), and the overall situation looks like it's ready to crah (again). Should you buy bonds today? I would say no. Yield on the 10 year treasury has doubled since summer, and rising yields means bond prices are going lower. Don't buy things as they are going down. Rising interest rates are often a sign that the stock market is about to decline, so that's another reason not to buy stocks. Should you buy real estate or REITs? I think those are tied to interest rates as well, so don't buy those. Should you buy commodities like oil, gold, silver, copper? Personally, I'm buying into mining right now. You might decide that nothing is worth buying at this time, so you hold onto your cash and wait until something is worth buying.