AveXis Merger Arb

I initiated a position in AveXis Inc (Ticker: AVXS) via common and short Puts. On April 9th Novartis (Ticker: NVS) announced the acquisition of AveXis for $218 per share in cash via tender offer. The tender offer will officially commence ~ 10 days from the date of the merger agreement. I am currently modeling this deal to close by June 15^th. The reason I like this deal so much is that the risk of this deal breaking due to an adverse event from the clinical trial is pretty much nil. During the conference call an analysts asked a question regarding the impact on the merger from an “unexpected event in one of the clinical trials that questions the safety potential of the product”. Novartis’ Head of Business Development responded with the following: “So in regard to unexpected events, we do not have an out, if there is an event opportunity.” I’ve never seen this before where the acquirer has no outs at all… AveXis is currently trading at $211.14, which still presents an attractive annualized return of ~ 17% (assuming a close by June 15^th).