After posting losses in two consecutive trading sessions, major indexes rebounded yesterday (Apr 6). The S&P 500, Dow Jones Industrial Average and Nasdaq rallied a respective 1.1%, 0.6% and 1.6%. The rebound was primarily driven by easing concerns over the Fed’s rate hike, uptick in crude oil price and an overall improvement in the healthcare space.Recently released minutes of the March 15-16 FOMC meeting showed that the Fed is not positive about the health of the global economy and will prefer to maintain a cautious approach in the near term. The minutes suggested that the Fed is unlikely to raise interest rates before June this year.Meanwhile, crude oil price jumped after data demonstrated a decline in U.S. inventory last week. The Energy Information Administration stated that oil inventories fell by 4.9 million barrels in the week ended Apr 1. Additionally, U.S. refineries used over 16.4 million barrels a day on an average, up 199,000 barrels from a week earlier. Meanwhile, refiners operated at 91.4% of operable capacity last week.Further, U.S. drug maker Pfizer Inc PFE and Ireland-based Allergen AGN called off their merger agreement following the tougher tax inversion rules imposed by the U.S. Treasury Department and Internal Revenue Service. The news led to an appreciation in the prices of the healthcare stocks. Also, at the end of the day, the S&P 500 Health Care index increased 2.7%.Healthcare faces a number of headwinds in 2016 including drug pricing controversy, a changing competitive scenario and mixed earnings reports. China, oil prices and global terrorism are also playing a role in the overall performance of the sector. In such a scenario, the recovery in healthcare is encouraging.Innovative product pipeline, new product approvals and impressive performance by key products are the primary growth catalysts. Moreover, reasonable valuations make the smaller companies attractive acquisition targets. A few of the major healthcare companies like Pfizer are now rumored to be on the lookout for suitable deals.Key PicksWe have picked four stocks that have gained on the improvement in the healthcare space. These stocks have a Zacks Rank #1 (Strong Buy) or #2 (Buy) with VGM Score of ‘A’ or ‘B’. The VGM score (V stands for Value, G for Growth and M for Momentum) essentially highlights critical factors in a stock that have the potential to drive its price higher in the near term.AMAG Pharmaceuticals Inc. AMAG – Based in Waltham, MA, AMAG Pharmaceuticals is a specialty pharmaceutical company which focuses on the development and commercialization of drugs related to maternal health, anemia and cancer supportive care. This Zacks Rank #1 stock surged almost 6.3% to close at $25.13 on Apr 6. AMAG has a VGM score of ‘A’.Horizon Pharma plc HZNP – Dublin, Ireland-based Horizon Pharma is a biopharmaceutical focused on identifying, developing, acquiring and commercializing products to address unmet therapeutic needs in arthritis, pain, inflammatory and orphan diseases. This Zacks Rank #2 company gained almost 9% to close at $18.79 on Apr 6. Horizon has a VGM score of ‘A’.Akorn Inc. AKRX – Akorn manufactures and markets diagnostic and therapeutic pharmaceuticals in specialty areas such as ophthalmology, rheumatology, anesthesia and antidotes, among others. The company also markets ophthalmic surgical instruments and related products. This Zacks Rank #2 stock increased 7.7% to close at $24.97 on Apr 6. The company has a VGM score of ‘B’.Five Prime Therapeutics Inc. FPRX – This Zacks Rank #2 stock is a biotechnology company that focuses on the discovery and development of protein therapeutics that blocks cancer and inflammatory disease processes. Five Prime rose 7% to close at $45.80 on Apr 6. The company sports a VGM score of ‘A’.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report PFIZER INC (PFE): Free Stock Analysis Report ALLERGAN PLC (AGN): Free Stock Analysis Report AMAG PHARMA INC (AMAG): Free Stock Analysis Report AKORN INC (AKRX): Free Stock Analysis Report HORIZON PHARMA (HZNP): Free Stock Analysis Report FIVEPRIME THERA (FPRX): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research