In February, after being blocked by a federal court, Aetna and fellow health insurer Humana opted to terminate their $37 billion merger deal. According to Barron's, the news of a possible union of Aetna and CVS would raise competitive questions about the PBM market and the health insurance arena. "A Wall Street Journal report of potential acquisition of Aetna by CVS is not a complete surprise," Jefferies analyst Brian Tanquilut wrote in a research note late Thursday. "Both management teams have commented in the last 12 months about the need to more closely collaborate with key strategic partners, including each other. Strategically, the vertical integration of retail pharmacy, PBM and payor fits with broader health care themes of expanded access, consumerism and cost reduction. Further, it would address each company's need for a fresh script."