GLD is the first to market to invest directly in physical gold. The product structure reduced the difficulties of buying, storing and insuring physical gold bullion for investors. Actively traded, the shares provide deep liquidity. NAV for the fund is determined using the LBMA PM Gold Price (formerly the London PM Gold Fix), so GLD has an extremely close relationship with spot prices. Its structure as a grantor trust protects investors, trustees cannot lend the gold bars. However, taxes on long-term gains can be steep, as GLD is deemed a collectible by the IRS. Also, GLD's NAV has a larger handle, which corresponds to more gold exposure per share. As such, those impacted by per-share trading costs may prefer GLD over similar funds.