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 ...

Counties are colored red or blue when the % expected vote reporting reaches a set threshold. This threshold varies by state and is based on patterns of past vote reporting and expectations about how ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Eric's career includes extensive work in ...

Optical sensors are a broad class of device for detecting light intensity. This can be just a simple component for notifying when ambient light levels rise above or fall below a prescribed level, or a ...