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.
Jump in U.S. Treasury yields signals market fear that Fed is behind the curve on prices. The U.S. bond market has begun sending a message that inflation risks are rising and the Federal Reserve may be too slow to act, potentially marking a significant turning point in the economic recovery. In the past week, Treasury-bond yields have jumped to their highest levels since last spring.