SPDR Gold Trust First up this week is the SPDR Gold Trust ( GLD), a $71 billion ETF that buys physical gold and stores it in vaults under London. GLD's exposure to physical gold and status as an ETF has made it one of the most popular options for investors who want to add gold to their portfolios -- and this week might just be a good time to do that. GLD is actually a vestige from last week's column, when we looked at a throwback that was taking place in shares. As a reminder, a throwback happens when a stock breaks out above a resistance level, then returns to retest that level as a newfound support price. That's exactly what happened with GLD in the days since, as shares caught a bid around the $165 level and reversed higher. That doesn't mean that gold is headed straight up right now (even if the metal does offer plenty of macro reasons to be a buyer). But it does mean that this metal is providing a very low-risk buying opportunity. I'd recommend picking up a position in GLD at these prices with a protective stop right at this ETF's previous swing low at $157.