The emerging information-processing and decision-making literature indicates that individuals use heuristic procedures that simplify cognitive processing requirements. Judgments (particularly subjective probabilities) are based on limited processing of a proper subset of the available evidence. Tasks potentially calling for complex analysis are reduced to heuristic procedures and efficient information processing may result: these heuristics can however produce systematic biases and costly errors in judgement. People also exhibit cognitive biases that systematically affect judgments of statistical properties of random variables. The biases appear to be cognitive in nature and therefore are not due entirely to emotional, motivational, or cost-of-processing considerations. For some cognitive biases, a possible explanation has been suggested in the context of an heuristic processing procedure. The objective of this paper is to analyze and synthesize the currently available research on cognitive heuristics and information-processing biases from the perspective of research and actual financial decision situations. Important implications for users and designers of information systems will be discussed. One generic conclusion from the literature is that individuals appear to be inadequate “intuitive” statisticians; a need for formal judgment and decision aids will become clear.