Data processing apparatus comprises a processing element having an instruction pipeline to execute instructions and trace circuitry to generate items of trace data indicative of processing activities of the processing element. The trace circuitry generates items of event trace data in response to events initiated by execution of corresponding instructions by the instruction pipeline and also generates items of waypoint trace data in response to instructions, in a set of waypoint instructions, reaching a predetermined stage relative to the instruction pipeline. The trace circuitry generates position data, indicating a relative position with respect to execution of the corresponding instructions by the instruction pipeline, of one or more items of event trace data and one or more items of waypoint trace data.