The article exaggerates a little because they are buying bitcoins but not selling them according to the site that it links. They need to buy bitcoins to obtain assets for their fund, so it makes sense. Perhaps they were buying on Mt Gox before and now they can't.
Thats even better. Ppl whos serious about "cashing out" they would have sold to SecondMarket.
Otherwise, all the "dumps" on the exchanges are purely manipulations.... hoping to buy back lower. Its like musical chair game. Zero sum game at its best.