GLD holds physical gold bullion in HSBC vaults in London, with each share representing a fractional claim on actual gold. It is the world's largest gold ETF and the most liquid way to own gold exposure in an equity account without dealing with futures contracts, storage logistics or the operational risks of gold mining stocks. Gold performs well when real interest rates are falling or negative — the opportunity cost of holding a non-yielding asset is lowest when yields are low — when dollar weakness is anticipated, or when systemic financial risk or geopolitical uncertainty drives safe-haven demand. Gold does not generate any income, which means the 0.40% expense ratio represents a genuine cost that compounds over long holding periods. Over multi-decade periods, gold has roughly preserved purchasing power against inflation but generated minimal real returns, making it more appropriate as a hedge than a compounding asset. For investors, GLD serves best as a portfolio diversifier during periods of macro uncertainty, equity market stress or inflationary regimes — typically allocating 5-10% of a portfolio to provide meaningful diversification benefits without dramatically affecting long-term compounding.