system
A chat on subreddit /r/wallstreetbets
human
Your second point is my main concern. 
  
 Also will have to look up what an I bond is lol

gpt
I-bonds are purchasable through the US Treasury online or with your tax return. They pay a base interest plus the CPI inflation rate twice a year. Base interest is a joke, like 0.10%, but the CPI adjustment is whatever inflation was for the preceding 6 month period.