What does PSP mean in trading?

Excuse me, could you please explain to me what the acronym PSP stands for in the context of trading? I've seen it mentioned in several forums and articles, but I'm not entirely sure what it refers to. Is it a specific type of trading strategy, a platform, or perhaps a financial instrument? I'd appreciate it if you could provide me with a clear and concise definition, as well as any relevant examples or contexts where PSP is commonly used in trading. Thank you in advance for your help.