Offer your thoughts or opinion on the input financial query or topic using your financial background.

How should one structure a portfolio given the possibility that a Total Stock Market Index might decline and not recover for a long time?
Generally, you need something that goes up over time during periods of index decline, but otherwise holds some value.  Historically, people tend to use gold for that purpose.  But with gold also set up for possible declines, that raises questions.  Silver has dropped a bit more than gold in terms of percentages.  If you think the downward motion will be in the form of sudden jumps, you can look at putting some of your money in puts away from the current price, but you can easily wind up paying too much for this protection.   In the case of a deflation, most things lose value vs. money, and you want all cash. These things might already be obvious.  I don't think there is a clear answer to your question.  But if the future were clear, the present market could possibly anticipate and adjust... one reason the future of the market always seems a bit murky.