system
A chat on subreddit /r/wallstreetbets
human
Short explanation: 
  
 You have a call for TSLA at $500. That means you bought the right to buy Tesla at $500. 
  
 Now Tesla will be offering stock at $420. Would you rather pay $420 for something or $500? 
  
 Therefore those calls are worthless because Elon basically put a cap on valuation. TSLA won't get to $500 unless it remains public and won't go private

gpt
They aren't offering stock at $420. They're buying back stock at $420. If loads of people want to buy Tesla stock and haven't gotten in yet, this is their last chance. We should see the price go well above $420, as everyone is guaranteed at least $420 for their stock. Then add in the extrinsic value of holding stock in a highly desirable private company.