The process of narrowing the exceedingly large universe of investable securities down to a manageable size so that remaining candidates are those which more likely possess the desired value characteristics. Security screening is a part of the broader portfolio construction process which involves limiting the security universe to some reasonable number of candidates that will undergo more detailed analysis. Every portfolio manager uses some type of screen. Screening is particularly necessary because it helps reduce the amount of time needed for making investment decisions. In the realm of investment, there simply is not time to research every security and process the available inputs. Screening or picking stocks is more an art than a science and there is no single optimal way to sift through portfolio candidates.