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. Suzanne is a content marketer, writer, and ...

Angelica Leicht is a seasoned personal finance writer and editor with nearly two decades of experience but just one goal: to help readers make the best decisions for their wallets. Her expertise spans ...

Sonotrax Basic is a high performance model with FHR digital LCD display. Sonotrax Pro has backlight and audio playback. All these models have audio output, which can be connected with earphone or ...