Pandaok, the calculator you show for options pricing appears to...

Pandaok, the calculator you show for options pricing appears to neglect one key metric which is liquidity. The oppies are not as liquid at the fully paids, easily seen by the buy/sell gap on the oppies. It is for this reason that the oppies will trail behind their "theoretical price". However, this does provide a decent arbitrage opportunity if the intent is to buy the oppies then pay the exercise price. I hold both fullies and oppies.