The share price drifting down due to option expiry is both a...

The share price drifting down due to option expiry is both a direct and indirect effect, in my opinion.

Certainly, there would be some who are selling heads to fund the exercising of options, but you also have those that are trading their heads on the wager that they can purchase them back at a lower price during an anticipated drift downwards, and others who are waiting on the sidelines to get a feel for the bottom before entering the company or expanding their holdings.

A chief difference between NVA and ADN is the anticipated flow of news. NVA had a resource estimate due after the expiry of options, so no anticipated sudden changes in trajectory until then. Conversely, ADN could drop a number of announcements which completely change the course of the share price before the options are due to expire, so one sells/holds off buying at the very real risk of this. I am absolutely not prepared to gamble my holdings for the sake of a few pips, but to each their own.