Cassava Sciences is developing an Alzheimer drug, which not just slow the disease, but reverses it! In February they announced some incredible data for their 6-month open label study. That was the reason for the massive price increase. After that, the share price started declining due to some uncertainty. But last week they announced to present the 9-month data set on a huge scientific conference.
For me that's a very very positive signal! Just imagine - would you present a failure on such a big stage? Certainly NO! Personally I used this opportunity to buy more shares.