Because some people buy JASO because they feel that investing in solar is good but they don't know what to buy. So, they buy a little YGE, JKS, JASO, etc. Then this helps to burn the shorts which are very much here because this stock is highly manipulated to the lower and upper side. (more to the lower obviously).
Then there are good news with CSIQ and the US solar companies and probably no EU import tariffs.
The question is is this the best stock to invest in? It lost 85 cents a share. HFT may burn some shorts but HFT may take the stock down exactly in the same way. Buy SPWR and be calm till the stock reach $120.00 soon. Some good projects will be announced in Inner Mongolia and Saudi Arabia.