  In the prospect theory, value function is typically concave for gains,
commonly convex for losses, with losses usually having a steeper slope than
gains. The neural system largely differs from the loss and gains sides. Five
new studies on neurons related to this issue have examined neuronal responses
to losses, gains, and reference points. This study investigates a new concept
of the value function. A value function with a neuronal cusp may show
variations and behavior cusps with catastrophe where a trader closes one's
position.
