SPDR Gold Trust (NYSE:GLD) — This ETF seeks to replicate the price of gold bullion net of expenses.

GLD had a terrific run from $80 a year ago to the recent new breakout high at over $175. But last week’s decision by the CME to increase margin requirements and its very steep line of advance tell us that a pullback is likely before the bullish advance resumes.

The first attractive entry point is at the 20-day moving average (green line), but extreme selling could take GLD back to its 50-day moving average at $155.

Since commodity ETFs may be subject to greater volatility than traditional ETFs, they may not be suitable for all investors. Traders should enter stop-loss orders to protect against large losses.