SandRidge Permian Trust (NYSE:PER) is an oil and gas trust that owns royalties to wells in west Texas. Over the past two years, PER has frequently ranked among the top trusts that I follow in terms of value and I've maintained a long position. However, times are changing. While PER's share price has been on a tear, the trust's underlying fundamentals have shown consecutive weakened quarters. I'm selling my long position and this article discusses the reasons why. As those familiar with my articles know, I analyze oil and gas trusts using a bottom-up, engineering-style model that forecasts future distributions. The forecasts are based upon a trust's historical performance, NYMEX commodity futures, trust agreement terms, and other relevant information. For PER, the most meaningful assumptions are: Read more