Researchers are concerned about the impact of climate change on bond markets.
There were 37 thunderstorms last year that each cost at least $1 billion, a new report says.
Bond investors avoided any payouts after the storm because of the fine print.
The overall market for cat bonds reached $46.5 billion in the first half of the year.
Sophisticated catastrophe models are helping bondholders sidestep large losses from weather-related calamities.
Issuance of catastrophe bonds is set to hit a record this year.
Cat bonds can leave investors with huge losses if disasters happen and huge gains if they don't.
The risk models behind the world's best hedge fund strategy are getting a lot harder to crack.
Investors who hold these bonds gain outsize profits if a contractually pre-defined catastrophe doesn't occur.
A large chunk of last year's losses stemmed from “relentless” thunderstorm activity, according to Aon.