system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What are bearer bonds? How do they work?

Just watched Die Hard and in the film the excellent antagonist Hans Gruber is trying to steal over $600 million in German bearer bonds from the Nakatomi corporation. It occurred to me that I have no idea what they are or why a company would have them.
gpt
There are two parts, Bearer, And bond 

Back to front, for the purpose of explanation. 

a bond is just a debt to be paid back in a certain manner, normally with interest, at a certain time.  
“X loaned Y $100. Y will pay back $200 in 2 years.”   
Bearer just means who ever holds it, or *bears* it, is owed the debt.   
So it’s “who ever has this paper, Y will pay back $200 in 2 years.”   
Effectively it’s just a piece of paper that has value to it… so it’s nearly as good as cash for a lot of purposes. 

They’re not common anymore due to them being used in various manners like money laundering or theft.