Total assets: US$13.01 billion; unit price: US$25.66

As the iShares Silver Trust’s website warns, it is not your standard ETF. Why? Put simply, the iShares Silver Trust is not an investment company registered under the Investment Company Act of 1940, or a commodity pool under the Commodity Exchange Act. Further, its ETF shares aren’t subject to the regulatory requirements that apply to mutual funds.

Investors who are not put off by those conditions may find the iShares Silver Trust appealing. It uses the London Bullion Market Association silver price as its benchmark and holds silver bullion — 465.55 million ounces as of the date noted above, to be exact. The trust has a five year total return of 13.49 percent.

Total assets: US$1.34 billion; unit price: US$27.06

The Aberdeen Standard Physical Silver Shares ETF is also not a typical ETF and is very similar to the iShares Silver Trust. The investment objective of the Aberdeen Standard Physical Silver Shares ETF is for its shares to reflect the performance of the silver price less the expenses of the trust's operations.

The fund is backed with 45.51 million ounces of silver held with JPMorgan Chase Bank in London in a secured vault. This ETF reportedly has a good record for correctly tracking the spot price of silver. Its five year average annual return comes in at 13.71 percent.

Total assets: US$570.83 million; unit price: US$33.80

Set up in December 2008 by ProShares, the ProShares Ultra Silver ETF was designed to offer daily investment results, that correspond with twice the daily performance of the Bloomberg Silver Subindex.

The fund uses derivatives such as futures contracts to invest in silver. ETF Database suggests it may be "a powerful tool for investors with a bullish short-term outlook for silver." While designed for short term investment, its total five year return stands at 8.74 percent.

Total assets: US$76.2 million; unit price: US$11.64

Alongside the creation of the ProShares Ultra Silver ETF in late 2008, ProShares launched its UltraShort Silver ETF. This fund was designed to provide investors with a hedge against declines in the silver market.

Because the fund is built around providing results at a negative two times daily performance of the Bloomberg Silver Subindex, it is meant for traders who have a high capacity for risk and who are willing to monitor their positions on a daily basis.

This high-volatility fund provides exposure to the silver futures market and has a five year return of -40.56 percent.

Total assets: US$1.02 billion; unit price: US$30.44

The Global X Silver Miners ETF gives investors access to a basket of silver-mining stocks. The ETF benefits from the fact that those companies can enjoy quick gains when the price of the metal is rising. It also allows investors to avoid the risks associated with individual companies and lets them add geographical diversity to their portfolios.

This ETF has an expense ratio of 0.65 percent, and its top holdings include streaming company Wheaton Precious Metals (TSX:WPM,NYSE:WPM) at a weight of 25.94 percent, Pan American Silver (TSX:PAAS,NASDAQ:PAAS) at a weight of 14.06 percent and Korea Zinc Company (KRX:010130) at 5.49 percent.

The five year average annualized return for the fund is 4.3 percent.

Total assets: US$875.89 million; unit price: US$10.96

The Amplify Prime Junior Silver ETF bills itself as the "first and only ETF to target small cap silver miners." The index provides a benchmark for investors to track public small-cap companies in the silver space.

The ETF has an expense ratio of 0.69 percent and its holdings span Canada, the US and the UK, with key silver companies such as Pan American Silver at a weight of 8.95 percent, Harmony Gold Mining (NYSE:HMY) at 7.92 percent and Coeur Mining (NYSE:CDE) at 7.16 percent.

Over the last five years the fund has provided investors with a return of 2.62 percent.

Total assets: US$213.67 million; unit price: US$11.52

The iShares MSCI Global Silver Miners ETF tracks an index composed of global equities of companies primarily engaged in silver exploration or metals mining; however, it skews toward Canadian mining stocks. The ETF has the lowest expense ratio of the three ETFs focused on silver stocks at 0.39 percent.

Holdings for the iShares MSCI Global Silver Miners ETF include Pan American Silver at a weight of 21.69 percent, Hecla Mining (NYSE:HL) at 9.66 percent and Newmont (TSX:NGT,NYSE:NEM) at 7.51 percent.

The five year total return for the fund is 5.94 percent.