CHICAGO--(BUSINESS WIRE)--Fitch Ratings has assigned a rating to the principal at-risk variable rate notes issued by Acorn Re Ltd., an exempted special purpose insurer in Bermuda, as follows: --$300,000,000 series 2015-1 class A principal at-risk variable rate notes scheduled redemption date of July 17, 2018, 'BBsf'; Outlook Stable. The notes provide reinsurance protection to Hannover Rueck SE (rated 'AA-', Outlook Stable by Fitch). The notes are exposed to Earthquakes for an area that includes