Fig. 4.

Association between IMs and trading. (A) The probability density of observing any trade (black line) and IM (green dashed line) in each hour on average across the observation period. Approximately 95% of trades and IMs are done between 9:30 AM and 4:00 PM, which corresponds to the main operation hours of the NYSE. (B) The empirical relationship (P < 10⁻¹⁰ using Markov randomizations) between the IM–trade coupling θ_ij and synchronous trading s_ij for all traders across the observation period. The dashed line depicts the association estimated via a linear regression (Materials and Methods).