Dive Brief:

• Nashville-based hospital operator HCA Holdings—the largest US hospital operator by sales—will replace grocer Safeway on the S&P 500; Safeway is being snapped up by private-equity firm Cerberus Capital.
• The healthcare segment on the S&P has been "on a tear," according to Barron's, and has climbed 24.5% over the past 12 months. 
• News of HCA's S&P 500 move boosted shares 3.6% in after-hours trading, and HCA is up 44% over the past year.

Dive Insight:

Acquisitions are hot in healthcare right now, and analysts are all (mostly) waxing poetic about the potential of HCA Holdings, which is reportedly planning a number of hospital-system acquisitions in 2015 and giving fellow giants like California-based Prime Healthcare a run for their money.

"We are looking for size—large systems, often not-for-profit," HCA CFO Bill Rutherford recently said at the JP Morgan Healthcare Conference in San Francisco. 

But as big acquisitions continue over the next several months, we could see an uptick in antitrust investigations, too. As TheStreet noted, HCA was recently on the losing side of a deal to purchase Kansas City, MO-based not-for-profit Carondelete Health, due to antitrust issues that arose with the Federal Trade Commission (Prime ended up the winner in that one).