The three largest biotechnology exchange traded funds are down over the past month by an average, gasp, 1.6%.

That modest number has been enough to elicit the tired fears that sector is richly valued and overdue for a more significant pullback. There is nothing like some more biotech mergers and acquisitions to set straight the industry’s critics and that is what is happening Wednesday as shares of Synageva BioPharma (NasdaqGM: GEVA) are up more than 110% after Alexion Pharmaceuticals (NasdaqGM: ALXN) said it will pay $8.4 billion for the rare disease treatment maker.

The price Alexion is paying is paying for Synageva ($230 per share) is seen as high when considering Synagenva lost $60 million in the first quarter and currently has not products on the market. However, the impact on biotech ETFs is palpable.

To this point in Wednesday’s session, two of the top four ETFs in terms of percentage gains are biotech funds, including the ALPS Medical Breakthroughs ETF (NYSEArca: SBIO). Proving that a big jump for a stock that does not command a huge percentage of a biotech ETF can still jolt the fund, SBIO is up 5.4% thanks to 3.64% weight to Synageva. That makes the stock the ETF’s sixth-largest holding. [These ETFs Will Like the Dyax News]

SBIO, which debuted on the last day of 2014, tracks the Poliwogg Medical Breakthroughs Index (PMBI), which is comprised “of small-cap and mid-cap pharmaceutical and biotechnology stocks listed on U.S. stock exchanges that have one or more drugs in either Phase II or Phase III U.S. FDA clinical trials,” according to a statement released by ALPS.

Companies with market values in excess of $5 billion do not gain admittance to SBIO. The result is a limited of treatments produced by SBIO holdings having as of yet reached Phase III trials. However, the advantage is the ETF could notch handsome rallies as its holdings navigate the FDA trial process. SBIO is off to a solid start, amassing nearly $57 million in assets under management while returning 21.1% in less than five full months of trading. [Healthcare ETFs up at Least 10%]

Modest weights to Synageva are helping other biotech ETFs as well. For example, the $2.2 billion SPDR S&P Biotech ETF (NYSEArca: XBI), the third-largest biotech ETF by assets, has 1% weight to Synageva, which is good enough to have the ETF up 2.6% today.