The global Companion Diagnostics Market size was estimated at USD USD 4.2 Bn in 2021, growing at a CAGR of 13.2% during the forecast period 2021-2027. Companion diagnostics are medical devices, often an in-vitro device and provides the information that essential for safe and effective use of the corresponding drug or biotechnology product. Companion diagnostics are often developed along with drugs to aid in selecting or excluding the patient groups for the treatment with particular drug on basis of their biological characters. Companion diagnostics are developed based on biomarkers technology to predict response or severe toxicity of the drugs or biotechnological compounds. Companion diagnostics are majorly used in oncology area. The Global companion diagnostics market growth is highly fragmented due to the presence of several established large and small suppliers. The competition in the market will intensify during the forecast period as vendors adopt strategies like M&A to develop new technologies. Product approval and launch will also help to increase the volume of available diagnostic devices in the market. In addition, the vendors also work on differentiating their products based on quality, the accuracy of results, and other value-added services as it will help them to gain a competitive edge over their peers.