Nuclear. Once operational, nuclear power is seen as the cheapest kind of energy, but the industry is still grappling with the issue of nuclear waste. The largest nuclear ETF is Market Vectors Nuclear Energy ETF (NYSE Arca: NLR),  currently up 21.7% year-to-date, with $166 million in assets. NLR has a 40% allocation to uranium miners, with other weightings in power generation and plant construction firms.

Commodities. ETFs are an easy way for a commodity trader to access this area of the market. The largest hard asset commodity ETF is Market Vectors Agribusiness ETF (NYSEArca: MOO), currently up 40% year-to-date, with $1.5 billion in assets. Other areas include water resources, steel, timber and broad-based commodities.

ETF MOO

Infrastructure. Infrastructure covers companies involved in construction and repair of roads and bridges, building and maintaining power grids, telecommunication networks and sewage systems. Worldwide stimulus funds have been steadily injecting more money into the sector. The largest infrastructure ETF is iShares S&P Global Infrastructure Index Fund (NYSE Arca: IGF), currently up 12.9% year-to-date, with $267 million in assets.

ETF IGF

Transportation. There’s no denying the economic impact of transport systems. The Claymore/Delta Global Shipping ETF (NYSE Arca: SEA) is currently up 25.9% year-to-date, with more than $70 million in assets. SEA is a good indicator for economic activity and commodities demand.

ETF SEA

Green. The green sector provides environmentally-friendly technology for an evolving society. The largest green ETF is PowerShares Cleantech Portfolio (NYSE Arca: PZD), currently up 29.8% year-to-date, with $145 million in assets. PZD tracks the performance of companies whose products improve productivity while reducing consumption of natural resources.

ETF PZD

Other. Or “miscellaneous” category that includes gaming, luxury items and Chinese real estate to name a few. The largest ETF in this area would have to be Market Vectors Gaming ETF (NYSE Arca: BJK), currently up 46.7% year-to-date, with $108 million in assets. BJK tracks global gaming companies.

ETF BJK

Max Chen contributed to this article.