Gold and gold mining shares are hot in 2016, just like their ETF’s. An ETF is an Exchange Traded Fund and makes it easier to buy gold and a group gold mining shares. Buying gold is just a mouse click away, but it’s so easy investors forget there is also some danger.

So, before you buy a gold ETF ever again, it’s important to know some facts and figures.

# 1. There is more gold than GLD

SPDR Gold Trust ETF (NYSE: GLD) is the biggest and most popular ETF to track the price of gold. It’s market cap is around $35 billion. At the height of the gold mania in 2011 GLD was even bigger than the SPDR S&P 500.

But most investors think GLD is the only way to track the price of gold, but there are others. The one you should put your eye on is iShares Gold Trust ETF (NYSE: IAU). This ETF has a market cap around $8 billion, so it’s not small. But it’s 25 basis points cheaper than GLD.

# 2. There are gold future ETF’s

GLD and IAU track the price of gold by buying physical gold. But you can also buy gold futures like the ones traded at the COMEX. PowerShares DB Gold ETF (NYSE: DGL) and UBS ETRACSCMCI Gold Total Return ETN (NYSE: UBG) are 2 gold future ETF’s.

It’s important to remember gold futures are more expensive when gold trades in contango but it’s cheaper when gold trades in backwardation.

# 3. Comparing GDX and GDXJ

Two of the most popular gold miner ETF’s are VanEck Vectors Gold Miners ETF (NYSE: GDX) and VanEck Vectors Junior Gold Miners ETF (NYSE: GDXJ). Most investors think GDX is for the big gold miners and GDXJ is for the junior miners and small caps. This is true at some point, but …

The top-5 holdings at GDXJ are also in the GDX-ETF, albeit with less weight. So don’t just buy GDX and GDXJ for a good diversification among gold mining shares. Both have more in common than you might think.

# 4. Gold with leverage

Leverage can be a beautiful thing when the price goes up, but it can destroy lots of capital when the price goes down. VelocityShares 3x Long Gold ETN (Nasdaq: UGLD) tracks the price of gold with a 3x leverage, it’s up 60% in 2016. ETF Direxion Daily Gold Miners Index Bull 3x Shares ETF (NYSE: NUGT) tracks gold miners and is up 300% in 2016.

But as you can see, they have a long way to go.

# 5. Don’t buy gold ETF’s to protect your wealth

Gold ETF’s like GLD and IAU are no physical gold, they track the price of gold. It’s hard to nearly impossible to ask for your share from the gold vault. When you want gold as a hedge against monetary disaster, you buy gold bars or coins. The only gold ETF that provides physical delivery is the VanEck Merk Gold Trust ETF (NYSE: OUNZ).