I do think it sounds plausible and has promising research support, and it remains to be seen if it's true, and if 2-73 is a therapeutic agent in this theory, and if it is effective in humans against real disease. These are the risks we are taking (along with the risk that Anavex can bring a drug to commercialization ("execution" risk), which is relatively much smaller, but real).
I have 50K shares in AVXL and they're just this side of green again today, as I see. My concern is what side it will be on a couple years from now. GLTY!