Examples
Company A common stock traded and quoted on the New York Stock Exchange
Company B common stock traded and quoted only on an inactive market in an emerging country
A privately placed bond of Z whose value is derived from a similar Z bond that is publicly traded
An over-the counter interest rate swap, valued based on a model whose inputs are observable such as LIBOR (London Interbank Offered Rate) forward interest rate curves.
A long-dated commodity swap whose forward price curve, used in a valuation model, is not directly observable or correlated with observable market data
Shares of a privately held company whose value is based on projected cash flows