### Comment:
Probably a short straddle.    
  
 This gains on rising price for DHR,   
 which was as low as 136 on Nov 11,    
 and is now (Dec 12 2019, mid-day) around 151.

### REPLY:
I understand that, but for every short position someone has to buy. There has to be an open long position too. This isn't just volume, this is 800k open interest. 
  
 Unless someone is just abusing some sort of algo buy?

### END.