For any number crunching work, be it making a report or developing a model or doing data diagnostics, visualization of the data is imperative. Be it univariate or multivariate data, visuals help us to look beyond the summary statistics or test statistics. For someone working in finance, there is an entire discipline of `Technical Trading' where buy , sell , stop-loss decisions are made based on visuals. Whether one believes it or not is a different question altogether.