system
A chat on subreddit /r/wallstreetbets
human
If two orders are processed as market orders and arrive at basically the same time the larger order is processed first if they cannot be processed simultaneously

gpt
This is only true if the counter party on the trade trade is FOK. Otherwise it is first in first out.  
  
 One will be .0001 seconds faster.  
  
 That said, Robin Hood is there to be the lube in a market makers ass. It is not for the $29 worth of nickels SPY traders benefit.  
  
 I wonder how many orders Robin Hood even puts in that are round lots.