Dow component UnitedHealth (NYSE: UNH) has made overtures for rival Aetna (NYSE: AET) while Aetna has been reportedly eying Humana (NYSE: HUM), according to the Wall Street Journal.

Any deals involving UnitedHealth, Aetna, Cigna, Anthem and Humana are likely to involve price tags that are seven or eight times, or more, larger than the $6.8 billion Centene is paying for Health Net. That $6.8 billion is also comparatively small to other deals that IHF constituents have engaged in. For example, UnitedHealth agreed to acquire Catamaran for $12.8 billion in cash earlier this year. In 2012, Express Scripts (NasdaqGM: ESRX), IHF’s second-largest holding, sealed a $29 billion acquisition of Medco. [More M&A Coming for This Healthcare ETF]

IHF’s primary rival, the equal-weight SPDR S&P Health Care Services ETF (NYSEArca: XHS), is also trading slightly lower today though it does not hold shares of Centene or Health Net.

Still, it is impossible to say investors are not enthused by these ETFs. IHF and XHS are up 21% and 17.1%, respectively, this year. IHF has added over a third of its $1 billion in assets under management this year while XHS has seen $60.6 million of its $197.8 million in AUM arrive since the start of the year.

iShares U.S. Healthcare Providers ETF