system
A chat on subreddit /r/wallstreetbets
human
Can you explain this a bit? I was flagged pdt somehow while closing spreads and it never made sense to me, but one of the legs got exercised

gpt
Well if you bought a call lets say @100 than you can close the position by selling a call at 101. Than you have a net position of +1 @100 call amd -1 @101 call. Almost the same as closing your position. 
  
 If you buy a 100 put you do the same by selling a 99 put. The next day you just close your +1 and -1 position at the same time 
 This way you can open and close positions without being flagged as PDT