At the time the deal was announced, Idenix was PBE’s ninth-lagest holding with a weight of 3%. The ETF enters Monday with 3.48% allocation to InterMune, enough to make the stock the fund’s tenth-largest holding. [Why These Biotech ETFs are Surging]

InterMune occupies weights of 1.54% and 1.16%, respectively, in the SPDR S&P Biotech ETF (NYSEArca: XBI) and the iShares Nasdaq Biotechnology ETF (NasdaqGS: IBB). IBB is the largest biotech ETF with almost $5.3 billion in assets.

First Trust NYSE Arca Biotechnology Index Fund

ETF Trends editorial team contributed to this post.