Advantage/disadvantage of using a Fok order?

Dark liquidity in options is when a MM shows a 10 up market, but is a really more than 10 up for their routing customers. So displayed liquidity is smaller than actual liquidity because the balance over 10 is dark and generally not available to customers not on their router.

 

So if the ceiling and bottom shows a lot of asks can I assume there is dark liquidity beyond that, or wouldn't that even show up at the +/-10 ask?

 

You can assume little. Dark liquidity isn't available to anyone without a routing deal to that MM.

 

So you say volume trading is a scam/rubbish?