The excitingly named Alan Smith is just making the banal but reasonable point that, by the very nature of what is driving the movements in the first place, hype will tend to push selling when things drop (and push buying when things rise). But if you buy into the idea that the stock market will rise over the long term, don’t lose heart just because it has dropped in the here and now. That drop is just part of the process, and can be seen as an opportunity if you have money to invest.
The thing that is missed from this analysis is that “the market” isn’t some external force of nature that just does its ineffable thing, leaving humans to ride it as best they can. The market is made by the practices of the humans that are constructing it. Booms are created by the same practices that lay the seeds for the coming bust. For the likes of you and I, that changes nothing. Invest what you can afford to for the long term and try not to worry. But as a piece of social critique, I think it’s important not to let market essentialism go unchallenged.