Have you ever wondered why gold and gold exchange traded funds (ETFs) are the safe-havens of choice for so many investors? There’s a very good reason for that.

Jacob Goldstein and David Kestenbaum for NPR have the answer. In a recent episode of the Planet Money podcast, they point out that gold is the perfect element to store value. The element is not a gas, doesn’t corrode or spontaneously combust, doesn’t kill you, is easily molded and is rare…but not too rare. [Why Junior Gold Miners ETF Shines.]

Gold surged more than 6% last week, bolstered by strong demand from China and India, as well as a weaker dollar, which fell 1.4% last week. The weakness in the unemployment report on Friday could support gold prices heading into this week. [What Affects Gold ETFs?]

The World Gold Council helped revitalize what was once a dying gold-mining industry and spent $14 million in creating the SPDR Gold Shares (NYSEArca: GLD), which is the 14th largest fund at $56.7 billion in assets, writes Barry Ritholtz for Business Insider. GLD is the largest private owner of gold bullion and purchases $30 million in gold daily. The fund has almost 1,300 metric tons of gold locked away in London vaults. It is calculated that gold-backed ETFs have added $100 to $150 per ounce to gold prices.

GLD is now one of several large physically-backed gold ETFs trading in the United States right now. iShares COMEX Gold (NYSEArca: IAU) and ETFS Physical Swiss Gold Shares (NYSEArca: SGOL) are two others; compare all three of them here to decide which is right for you.

For more information on gold, visit our gold category.

Max Chen contributed to this article.

The opinions and forecasts expressed herein are solely those of Tom Lydon, and may not actually come to pass. Information on this site should not be used or construed as an offer to sell, a solicitation of an offer to buy, or a recommendation for any product.