On tail risks, in this case the Wuhan virus, the way to think about it is yes there may be some very short term impact (sometimes there's even a trade there). However, we have to understand these short term tail risks are unlikely to have an impact that would swamp a well set up trade.
This is particularly true in the HK / China case. In the grand scheme of things, the impact is low (at this stage). Don't forget, the trade is premised upon a valuation move (rather than say earnings moves) so it's less important. Finally, Hong Kong has had a long history of dealing with these viruses, so from a competency point of view, it's very well managed and therefore even less likely to have significant impact (again, at this stage).
The impact is likely to be simply from a timeline point of view.