Options Steam Alert SRPT

A huge options order hit the tape just before the close in SRPT today.  It was by far the largest order I saw all day in the options market at a single strike in a single purchase. 

Alert: SRPT 4/29 20.0 Calls (Wkly): 800@$6.00. 847 traded today v 659 Open Interest.  Earning 5/5
$19.93 Ref. ($480,000 worth of calls purchased)

Here's some news I've found on the stock:

This "shot in the arm of confidence" comes in the form of a letter posted to the University of California, Los Angeles' website that urges the Food and Drug Administration to consider approving eteplirsen for the treatment of DMD. The letter was co-authored by the two co-directors of the Center for Duchenne Muscular Dystrophy at UCLA, and was signed by an additional 34 physicians, clinicians, and researchers who specialize in DMD research around the globe. According to reports, the letter was actually delivered to the FDA last month.
This letter represent the strongest pooling of public support for eteplirsen to date, but the drug still faces an uncertain future with an FDA PDUFA date of May 26, 2016. DMD is a disease diagnosed during childhood and characterized by a breakdown of the myelin sheath that protects muscle fibers, with most patients dying in their 20s.

Couple items to note:

1. The buyer of the calls paid $6.00.  The ask on these calls was only $5.80.  That meant they wanted to get filled before the close of the market today and weren't willing to wait or work the order for the best price.
2. The earnings are 5/5 which is usually a good catalyst for the stock to move.  These are purchased to expire before earnings on 4/29.  Also, the news catalyst in the form of the FDA decision is not until May 26th.  Clearly this buyer expects a big move prior to both events.
3. Breakeven at expiration is $25.93 at expiration. 

My Take: 

Generally when you see this much interest in a stock and their isn't a clear catalyst someone generally knows something.  Keep an eye on this one the next few days.  Might be worth dipping your feet in to participate in the move.