Hold Up is a game mechanic in Persona 5. It allows you choose between an All-Out Attack or a Special conversation by having the protagonist and the Phantom Thieves of Hearts surround the Demons and point their guns at them.
To initiate a Hold Up, you must Down all foes by targeting their weaknesses or by critically hitting them. A Hold Up is automatically initiated, from which you have the following options;
All-Out Attack
Begins an All-Out Attack that significantly damages all foes. In the event that you eliminate all foes with an All-Out Attack, the character that started the Hold Up will pose for a special shot, complete with a catchy phrase
Ex: If Morgana finishes the enemy with an AoA, a chair falls from the sky that he dramatically swivels in, smoking a cigar as a stamp saying "Mission Accomplished" is superimposed onto the background.
Conversation
Activates a negotiation segment similar to those of previous SMT games. The difference here is that most demons won't ask for items or money (considering that you're holding them at gunpoint). However, you will need to make the proper choices in the dialogue if you wish to get the demon to cooperate. If the negotiation succeeds, the demon can give you money, items, or become a new Persona for the Protagonist to use. If it fails, the Hold Up automatically ends and the targeted demon gets back up.