A permanent portfolio is a portfolio construction theory devised by free-market investment analyst Harry Browne in the 1980s. Browne constructed what he called the permanent portfolio, which he believed would be a safe and profitable portfolio in any economic climate. Using a variation of efficient market indexing, Browne stated that a portfolio equally split into growth stocks, precious metals, government bonds and Treasury-bills and rebalanced annually would be an ideal investment mixture for investors seeking safety and growth.

Harry Browne argued that the portfolio mix would be profitable in all types of economic situations: growth stocks would prosper in expansionary markets, precious metals in inflationary markets, bonds in recessions and T-bills in depressions. Acting on his beliefs, Browne eventually created what was called the Permanent Portfolio Fund, with an asset mix similar to his theoretical portfolio in 1982: 35% government securities, 20% gold bullion, 15% aggressive growth stocks, 15% real estate and natural resource stocks, 10% Swiss franc bonds and 5% silver bullion. Over a 25-year period, the fund averaged an annual return of 6.38%, only losing money three times. It outperformed the S&P 500 in the years immediately following the dotcom bust.

Although the fund was considered a successful investment for providing investors security with moderate growth, during the 1990s, the Permanent Portfolio Fund badly underperformed compared to the stock market. During that period, it was not uncommon for stocks the appreciate 20-30% annually, while the permanent portfolio rose just over 1% each year. Today, many analysts agree that Browne's permanent portfolio relied too heavily on metals and T-bills and underestimated the growth potential of equities and bonds.