system
A chat on subreddit /r/wallstreetbets
human
Most of the buyers of negative yield debt are institutional (pension plans, other governments, etc.) that are forced by mandate to own a portion of assets in sovereign debt. Buying a negative yield bond can be a 'good' investment for safety if it is expected that other assets are expected to decline faster in value than the negative interest. Negative rates exist specifically to discourage savings on the hope that money is invested into things that can expand the economy.

gpt
&gt; that are forced by mandate to own a portion of assets in sovereign debt. 
  
 'We're losing money' 
  
 'We should allow ourselves to buy more risky assets' 
  
 regulators: 'awww shit'