In a year in which healthcare exchange traded funds are dominating at the sector level, it is not surprising to see biotechnology funds shining particularly bright.

While some of this year’s best biotech ETFs are smaller, new breed, niche funds, the old guard of biotech ETFs are well represented among this year’s best funds. That includes the iShares Nasdaq Biotechnology ETF (NasdaqGS: IBB), which tracks the Nasdaq Biotech Index, and the SPDR S&P Biotech ETF (NYSEArca: XBI), the third-largest biotech ETF by assets. [Biotech ETFs for the Long Term]

IBB, the largest biotech ETF, is up 20.2% this year while the equal-weight XBI has surged nearly 31%.

“Biotechnology was the best performing sub-industry, up 288.5% from 2011-2014, ahead of the S&P Health Care Sector and the broader S&P 1500 indices gains of 118% and 64%, respectively. Year to date through June 6, the 9% gain for broader market’s 2.0% return. According to Jeffrey Loo, S&P Capital IQ’s head of health care equity research, there are a number of catalysts. He highlighted that in 2014 several high profile blockbuster drugs were approved by the Federal Drug Administration (FDA) and sales for the seven biotech companies in the S&P 500 index rose 41.5% in 2014, while net income rose 85%. Looking forward, these companies have robust pipelines, with expectations that 10-12 compounds could be approved by the FDA in 2015 and are capable of achieving blockbuster sales in five years,” according to a new research note from S&P Capital IQ.

As S&P Capital IQ notes, international equity ETFs have been the apples of investors’ eyes this year, but healthcare ETFs have been prolific asset gatherers at the sector level. No sector ETF has added more new assets this year than the Health Care Select Sector SPDR (NYSEArca: XLV), but IBB and XBI added $450 million and $485 million, respectively, through the first five months of the year, according to S&P Capital IQ. [Investors ran to Bank, Healthcare ETFs in May]