Investors in interest rate options are paying for trades that benefit from a sharp slowdown in the U.S. economy, contrary to the upbeat outlook held by many bond market participants. Analysts said they have seen increased demand from hedge funds in the U.S. options market for so-called "receiver swaptions," a type of trade that pays off when interest rates fall. In general, receiver swaptions give buyers the right to enter into an interest rate swap where they receive the fixed rate and pay the floating one.