### Comment:
Arbitrage has risk associated with it.  It's primary risk is erosion (typically due to competition), but you can get caught holding something if volume dries up. 
  
 Anyway, from what I gathered from the article, after roll-down, risk goes away and you get a positive expected outcome (the definition of no risk). 
  
 I would probably characterize it as a 'modal arbitrage'.

### REPLY:
&gt;you get a positive expected outcome (the definition of no risk). 
  
 lmfao you have no idea what you are talking about

### END.