What factors affect behavioral biases? Evidence from Turkish individual stock investors

• Using nationwide transaction data, we analyze several behavioral biases.
• Biases are common among investors and affected by demographic factors.
• Biases affect return performance of individual investors.

This paper investigates behavioral biases among Turkish individual stock investors during 2011. Using transaction data, we analyze how common disposition effect, familiarity bias, representativeness heuristic, and status quo bias are, what factors affect these biases and how these biases relate to each other including overconfidence and return performance. We find that biases are common among investors. Male, younger investors, investors with lower portfolio value, and investors in low income, low education regions exhibit more familiarity bias. Female, older investors and investors with high portfolio values are more subject to disposition effect and representativeness heuristic. Individuals in the opposite edge of overconfidence are subject to status quo bias. Overconfidence is positively correlated with familiarity bias. Representativeness heuristic deteriorates wealth while status quo bias results in higher trade performance. Familiarity bias has a nonmonotonic effect on return; lower (higher) levels of familiarity bias have a negative (positive) effect on return. To the best of our knowledge, this is one of the few studies that focus on nationwide data and analyze the biases simultaneously. Using a unique dataset, we extend the findings of the behavioral finance literature to emerging markets. Besides, analysis of multiple biases helps us better understand the relationship among biases.