I'd say the high put volume is a bullish sign. I think smart money is selling the puts and usually believe smart money sells options overall, this is because most options expire worthless. I sold 100 of the March $22 Put for 2.20 because I doubt this goes below $20 and probably trades highes as we approach spring time announcement of AA.
Look at Arena for example, there was massive open interest for the Jan calls, over 65,000 contracts at the $10 strick alone. Well, now that that's passed all of those options expired worthless. I think smart money is going long SRPT and accumulating during this down trend and selling puts as an easy way to make money.
Just remember, for all of these puts being bought, someone is collecting the premium and making some money. Only time will tell who's right but I am inclined to believe its the options sellers in this case, like in most. If big money spent $125 million betting on this I doubt it goes below $20 in the short term. There will be support from preventing a collapse and although the whole market can tank potentially if the bond market collapses, I find it highly unlikely to occur in the next 4 months by May.
Also, I was looking to buy SRPT calls but the premium is ridiculous. The May $30s are going for almost $5. At crazy prices like that I can understand why calls haven't been selling as high as puts. I am waiting for this to take a nice run up back to near 30, at which point I'll begin selling calls.