A photocell is any of a wide range of sensors that react based on the presence of light or electromagnetic energy. They can be found in many different forms, from solar panels that use light to generate electricity, to photoresistors, which shift in resistance based on how much light is present.
Bond prices and yields are like a seesaw: when bond yields go up, prices go down, and when bond yields go down, prices go up. In other words, a move in the 10-year Treasury yield from 2.2% to 2.6% indicates negative market conditions, while a move from 2.6% to 2.2% indicates positive market performance.
Understanding Yield and the Effects of Rising Interest Rates. Think of yield as the return provided by a fixed income investment. The yield of a bond is based on both the purchase price of the bond and the interest (or coupon) payments received each year. Yield is often the term used to describe long-term interest rates.