Systems and methods for identifying a pattern in data to detect a behavior of interest. The systems and methods receive a data stream representing a series of events occurring over a time interval. The systems and methods determine, for the interval, a depth indicating the amount of interest during the interval, where the interest represents an amount of a selected activity during that interval for a selected parameter. The systems and methods also generate a depth chart for the activities at different values of the selected parameter over a series of intervals, train a machine-learning image-classification model using depth chart images; identify the behavior of interest using predictions from the trained machine-learning model and target pattern; and provide an indication of the presence or absence of the behavior of interest. The parameter can represent a quantity and associated price of a commodity in a market.