Does venting emotion help a trader regain focus or does it exacerbate emotional and physical arousal and interfere with concentration and decision making?
Research actually suggests that venting emotion after a traumatic event can lead to worse psychological outcomes.
The key seems to be whether the venting allows for a reprocessing of the stressful events. If the venting leads to new ways to interpret what has happened--new perspectives--it can be helpful. If there is no such transformation of the stressful event, venting can simply amplify stress responses and reinforce them.
Venting in a social manner to gain control can constitute good coping. But losing emotional control simply reinforces a sense of lost control.
So, play him off: pissed trader.