Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Robert Kelly is managing director of XTS ...

When an investment you purchase increases in value, you have an unrealized gain until you decide to sell it, at which point you have a realized gain. Conversely, if an investment you own declines in ...

Bonds don't get as much attention in the investing world as stocks do, but they play an equally important function in investment portfolios. The predictable cash flows that bonds offer stand in stark ...

Oscilloscopes measure current and voltage and, through the magic of mathematics, calculate power. Unfortunately, power comes in a large number of guises: instantaneous, real, apparent, and reactive.

Daniel Jassy, CFA, is an Investopedia Academy instructor and the founder of SPYderCRusher Research. He contributes to Excel and Algorithmic Trading. Return on investment (ROI) measures the amount of ...