### Comment:
but IV kind of is circular.  it's an input to the pricing model, but derived from the pricing model. 
  
 my understanding is that it's first derived using the ATM market pricing and then OTM contracts are priced using this IV as input.

### REPLY:
But price is derived from transactions, not a model. So the IV is basically a plug from what premium people are willing to pay. People are willing to pay a premium if they expect the price to move a certain amount. Hence, implied volatility.

### END.