Context is key. It was quite obvious from the original post wanting to own shares specifically for what that would entitle them. Following that up with "don't you mean short it?" shows that the original point of the post was not understood. However, if you forget the above and focus on the one post, you lose site of the conversation.

Given that you have to infer meaning from context (which can be subjective; in this case, are you being snarky or not? (Not so, but there is ambiguity)), it is better to assume good faith in the question and respond directly. It lacks sophistication, but minimizes cross-talk as much as is feasible.