  Successful animal systems often manage risk through synchronous behavior that
spontaneously arises without leadership. In critical human systems facing risk,
such as financial markets or military operations, our understanding of the
benefits associated to synchronicity is nascent but promising. Building on
previous work illuminating commonalities between ecological and human systems,
we compare the activity patterns of individual financial traders with the
simultaneous activity of other traders---an individual and spontaneous
characteristic we call synchronous trading. Additionally, we examine the
association of synchronous trading with individual performance and
communication patterns. Analyzing empirical data on day traders'
second-to-second trading and instant messaging, we find that the higher the
traders' synchronous trading, the less likely they lose money at the end of the
day. We also find that the daily instant messaging patterns of traders are
closely associated with their level of synchronous trading. This suggests that
synchronicity and vanguard technology may help cope with risky decisions in
complex systems and furnish new prospects for achieving collective and
individual goals.
