Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Andy Smith is a Certified Financial Planner ...

Stiff person syndrome (SPS) causes you to have muscle stiffness and spasms, often triggered by sudden noises or touch. You can use medications like muscle relaxants and anticonvulsants to relieve ...

Jennifer M. Edwards is a journalist and author and certified personal trainer. She spent several years as the lifestyle editor for several daily newspapers in Texas, New York, and Florida. Her work ...