[GlennFarrant]

I believe the strongest, first order, signal for a rally that sticks will be when there's a somewhat effective treatment for the virus that can be deployed in a scalable way. This will mean that the healthcare systems will be under less pressure as they will be operating in a different mode and that will mean that restrictions that have a negative economic impact will be lifted.

Until then, there's always the prospect of resurgence of the virus once restrictions are lifted, and that will keep the lid on the markets.

If there's strong news of effective treatments in the short term, that may kick off a sustained rally soon.

Of course the other things you mention are very valid too and will have positive effects, and may be "the one".