The Bogleheads Permanent Portfolio is a tax-efficient variation of Harry Browne's Permanent Portfolio for US investors. It allocates 25% to each of these assets:
Total US stock market: Stocks of all sizes and sectors.
Total US bond market: Bonds of various maturities and credit ratings.
Intermediate-term TIPS: These are Treasury Inflation-Protected Securities, which means that their payments are adjusted for inflation.
Cash: Money market funds and short-term investments.