Biostockclub, thanks for the explanation - hadn't quite understood the motivation behind the preferreds earlier. Signal of confidence just like Misslings scheduled share purchase breadcrumbs now. (Not quite sure why he put preferreds to a vote back in 2015 though - too early in hindsight.)
Hoping any earlier dispersion in MMSE or ADCS/ADL or P300 among indiv. patient timeseries have tightened up towards the upside over these 1.5 years.