LONDON (Reuters) - Expectations that catastrophe bond investors will not lose money as a result of superstorm Sandy have been shaken by an estimate that losses for insurers from the Oct. 30 storm will top $20 billion.
A loss of that magnitude would trigger payouts on two catastrophe bonds sponsored by Swiss Re, the world's second-largest reinsurer, according to market participants.
Cat bonds transfer insurers' potential losses from the worst natural disasters to capital markets investors, who receive hefty coupon payments but risk losing all or part of their principal if an event such as a hurricane or earthquake occurs.
A payout is a rare occurrence, with only eight of some 210 property catastrophe bonds issued since 1997 ever being triggered.
Disaster modelling company RMS confirmed on Wednesday that it expects insured losses from the Category 1 storm which slammed into the east coast of the United States to reach $20 billion to $25 billion.
At the high end of the range, RMS's estimate exceeds those of peers AIR and Eqecat, whose top estimates were $15 billion and $20 billion, respectively.
Seen at risk of a payout that would prove costly for investors are tranches of two catastrophe bonds issued by Swiss Re through its Successor X and Mythen Re vehicles to cover the reinsurer against losses from U.S. hurricanes.
They are the $80 million F4 tranche of Successor X Ltd's Series 2011-3 bond and $250 million of class H notes issued by Mythen Ltd.
A Swiss Re spokeswoman said the firm could not comment.
Previous commentary from industry participants such as reinsurance broker Willis and credit rating agency Standard & Poor's had suggested Sandy's impact on catastrophe bonds would be muted.
A final decision on whether the bonds have been triggered will come when information-aggregator Property Claims Services (PCS) releases its loss data, which usually comes within 30 days of a storm making landfall.
U.S.-based PCS provides loss estimates which are used by the majority of cat bonds to define whether an insurance event qualifies for a payout under the terms of the deal.
Investors with knowledge of the transactions said it would take $16 billion in insured losses to trigger Successor X's F4 notes, and $22.4 billion of losses for a Mythen Ltd payout.
"Sandy may have caught a lot of investors by surprise," said one U.S.-based cat bond fund.
Some aspects of Sandy, such as the extensive flooding it caused, are reminiscent of 2005's Hurricane Katrina, claims from which crept up to more than $40 billion, making it the insurance industry's costliest-ever natural disaster and triggering losses on some cat bonds.