Its not every day that a stock comes public at $20 a share, falls 7 percent on its first day of trading and then continues to drift downward. Then again, if that stock is a mortgage investing real estate investment trust like Cherry Hill Mortgage Investment Corp., its no big surprise. Thanks to rising interest rates which actually have been in decline during the government shutdown and uncertainty over the U.S. debt ceiling mortgage REITs have been battered in the market. Cherry Hill, a spin-off of Freedom Mortgage of Mt. Laurel, NJ, went...