To be honest, I don't think the buy stock process was actually
intended to be one-click. Normally, the first click would be to the "buy" form, and then the second click would be the "buy stocks" button on that form. But apparently there wasn't any code that was checking whether the "buy" order was truly coming from the form. That's why I asked about the "oops! directed from wrong page" error - inserting that catch would help guarantee that stock purchases are coming from the actual form (and, in effect, make it two-click).
By the way - Neodaq's sheet doesn't do one-click buys, so it wouldn't break it.