The fall of the Tory party

I don't have time to listen to it at the moment but are you referring to UK government bonds and pension funds?

https://archive.is/iO2Mg

I wouldn't say "no one understood them" - the BoE specifically stepped in to prevent the situation from worsening. But they do seem to be complicated.

Either way my layman's understanding is:

• The UK government issues gilts which pay X% interest over whatever period of time, which you can buy for a price
  
• Government announced massive unfunded tax cuts which means they were going to have to borrow loads of money, which means the internet rate on gilts was likely to increase
  
• Gilt prices dropped off a cliff, because why would you buy a gilt that pays 2% when you can wait a few months and buy a gilt that pays 6% instead?
  
• Gilt prices falling has massive knock-on impacts on pension funds who rely on gilts and instruments based on gilts to have predictable income/growth
  
• Pensions were forced to sell off their own gilts to cover their liabilities
  
• Gilt prices fall even further causing more sell offs.
  
  

that no one had told truss & Kwarteng about

Also it's not just the case that no one told them. They deliberately avoided asking for advice from some of the budget/treasury bodies because they knew that what they had planned was bonkers.