Technology is the best performing sector this year with more than 20% gain, while the S&P 500 index is up about 11.5%. Within the broader tech sector, semiconductor stocks have been among the best performers.

There are many reasons behind this outperformance and why this trend could continue going forward. Most chip companies have reported better than results and this week’s results from Micron Technology (MU) confirmed the trend.

While some of the traditional business areas face challenges, like PC sales are slowing down and smartphones sales are becoming flattish, newer growth areas have emerged for chipmakers, including Autonomous Cars, Artificial Intelligence, Cloud Computing, Virtual Reality, Gaming, Wearables and Internet of Things (IoT).

There is a lot of innovation going on in the industry; chipmakers are adopting new materials and technologies to manufacture smaller and more efficient chips.

There are four semiconductor ETFs that investors need to know about.

iShares PHLX Semiconductor ETF (SOXX - Free Report)

SOXX is the most popular chip ETF with $1.2 billion in AUM. It’s a modified market cap weighted ETF. It has 30 holdings with a cap of 8% on individual securities and holds not more than five securities at that cap. The expense ratio is 48 bps.

Intel (INTC - Free Report) , Texas Instruments (TXN - Free Report) & Nvidia (NVDA - Free Report) are the top three holdings.

VanEck Vectors Semiconductor ETF (SMH - Free Report)

SMH has $926.61 in AUM. It’s a market cap weighted ETF. The expense ratio is 36 bps. It has a more concentrated exposure with top three holdings--Taiwan Semi, Intel & Nvidia--accounting for almost 30% of assets.

SPDR S&P Semiconductor ETF (XSD - Free Report)

XSD is an equal-weighted ETF with $306.69 M in AUM. It has an expense ratio of 35 bps. Equal weighting results in higher exposure to smaller companies than peers.

PowerShares Dynamic Semiconductors Portfolio (PSI - Free Report)

PSI is a smart beta ETF with $287.70 M in AUM. It evaluates companies based on a variety of investment merit criteria, including price momentum, earnings momentum, quality, management action, and value. It’s a bit pricey with an expense ratio of 63 bps, but has been the best performer this year.

To learn more about these ETFs, please watch the short video above.