Some ETFs are bigger, and more popular than others. Matt Hougan, IndexUniverse president of ETF Analytics, explains why some of his top ETF picks are worth your money.

See the full CNBC interview Below:

SPDR S&P 500 (NYSEARCA:SPY)

The SPDR® S&P 500 ETF is a fund that, before expenses, generally corresponds to the price and yield performance of the S&P 500 Index.

iShares S&P 500 Index (NYSEARCA:IVV)

The iShares S&P 500 Index Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of U.S. large-cap stocks, as represented by the Standard & Poor’s 500

PowerShares DB Agriculture (NYSEARCA:DBA)

The PowerShares DB Agriculture Fund seeks to track changes, whether positive or negative, in the level of the DBIQ Diversified Agriculture Index Excess Return™ (“DB Agriculture Index” or the “Index”) plus the interest income from the Fund’s holdings of US Treasury securities less the Fund’s expenses. DB Commodity Services LLC serves as the Managing Owner of the Fund. The Fund is designed for investors who want a cost-effective and convenient way to invest in commodity futures. The Index is a rules-based index composed of futures contracts on some of the most liquid and widely traded agricultural commodities. You cannot invest directly in the Index. The fund is rebalanced and reconstituted annually in November.   This Fund is not suitable for all investors due to the speculative nature of an  investment based upon the Fund’s trading which takes place in very volatile markets. Because an investment in futures contracts is volatile, such frequency in the movement in market prices of the underlying futures contracts could cause large losses. Please see the “Important Considerations” and Prospectus for additional risk disclosures.

iPath DJ-UBS Agriculture TR Sub-Idx ETN (NYSEARCA:JJA)

The Dow Jones-UBS Agriculture Subindex Total Return is a sub-index of the Dow Jones-UBS Commodity Index Total Return and reflects the returns that are potentially available through an unleveraged investment in the futures contracts on physical commodities comprising the Index plus the rate of interest that could be earned on cash collateral invested in specified Treasury Bills. The Index is currently composed of seven futures contracts on agricultural commodities traded on U.S. exchanges.

iPath S&P 500 VIX ST Futures ETN (NYSEARCA:VXX)

The S&P 500 VIX Short-Term Futures Index TR is designed to provide access to equity market volatility through CBOE Volatility Index® (the “VIX Index”) futures. Specifically, the S&P 500 VIX Short-Term Futures™ Index TR offers exposure to a daily rolling long position in the first and second month VIX futures contracts and reflects the implied volatility of the S&P 500® Index at various points along the volatility forward curve. The index futures roll continuously throughout each month from the first month VIX futures contract into the second month VIX futures contract.

A direct investment in VIX (commonly referred to as spot VIX) is not possible. The S&P 500 VIX Short-Term Futures™ Index TR holds VIX futures contracts, which could involve roll costs and exhibit different risk and return characteristics. Investments offering volatility exposure can have various uses within a portfolio including hedging, directional, or arbitrage strategies and are typically short or medium-term in nature.

NYSE:DBA, NYSE:IVV, NYSE:SPY, NYSE:VXX