It's all momentum, in my opinion. A big biotech firm announces news, everyone buys in...then CRA screws up relations with NIH, companies in their newfound popularity put out secondary offerings which dilutes the stock even more, people get impatient for lack of news to propel the stock to further unwarrented heights, and suddenly the money quickly starts drifting to other "hot" sectors.
Notice, for example, the total absence of spam anymore on this board since we've been drifting south? Frankly I almost prefer it this way.
I wouldn't worry about HGSI in any case. The company was doing well BEFORE all this biotech hype broke out and it will keep doing well even after the price settles down to a more reasonable level.
And we all know that with the next round of news, the price on these babies will all skyrocket back upwards again (e.g. when CRA announces its completion of sequencing the entire Human Genome). You can try to time it if you want - or you can just wait and hold and be rewarded.