Embeddedness in social networks is increasingly seen as a root cause of human achievement, social stratification, and actor behavior. In this article, we review sociological research that examines the processes through which dyadic ties form, persist, and dissolve. Three sociological mechanisms...

Using instant message communications and trading records of professional traders, we directly measure how investment information propagates in traders’ social networks and how it affects their trading decisions and performance. Traders are more likely to mention stocks with gains over losses,...