Cloud technology is playing a vital role in presentera to store and process massive amount of data, which leads to the convergence of cloud and big data. Cloud computing holds a tremendous promise of unlimited, on demand, elastic, computing and data storage resources. It has the potential to enhance business agility and productivity while enabling greater efficiencies and reducing costs. Big data environments require clusters of servers to support the tools that process the large volumes, high velocity, and varied formats of big data. It offers the promise of providing valuable insights that can create competitive advantage and also to explode new innovations. In this paper, I discussed how cloud and big data technologies are converged to improve quantitative decision making with minimal risk and to offer cost-effective delivery model for cloud-based big data analytics.