I think it would be hard to get into or out of AB Science since its a French company and has almost no volume on our exchanges. Athira would be easy enough and has basically doubled since they abandoned their previous business model, changed their name and IPO'd with their current molecule. They do have an interesting drug and a market cap that could double or triple depending on how their trial goes IMO.
I guess some of it just depends on how much money one wants to put into a lotto play vs the rest of their holdings. It's been such and incredible market run this year in just about every sector imaginable, especially the green energy stocks (just about any of them to be honest), but even PPE heavy banks like LOB (which was founded in town here), oil plays like USO, larger BP like BMY, companies that make the vials for covid like GLW, a diversified company like YUM even. Point being that when the markets are hot, and I've never had so many runners like this year, then its a lot more profitable to be diversified and just keep lesser positions in one or two of these lotto plays for the long haul. I expect a market pullback but I've been expecting that for a long while lol. JMHO