Principal-Protected Note - PPN
  
The basic dynamic of investing involves the possibility of losing money. You put money into a venture. You might get a nice return. The investment might go toe up.
Principal protected notes eliminate the downside. It’s like riding a bike with training wheels. Or like swimming with sharks who have had their teeth pulled.
The principal-protected notes guarantee the investor will at least receive their principal back. They might not make money, but they won’t lose money either. They have a guaranteed return of at least 0%.