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 ...

Among the many changes brought about by the pandemic is the widespread use of QR codes, graphical representations of digital data that can be printed and later scanned by a smartphone or other device.

Let me come clean: For way too long now, I’ve been excited about the 2D optical code format called QR Code. I even convinced TidBITS to put one on every article page for a while. I don’t get a ...