Why The Sales Of Moderna Stock Are Raising Eyebrows

The sales of company stock by executives at Cambridge-based coronavirus vaccine developer Moderna are raising eyebrows.

An investigation by NPR has found that the biotech company's executives have sold $90 million worth of Moderna stock since June 1. That comes after executives sold off stock in May.

Mark Williams, a master lecturer in finance at Boston University, joined WBUR's All Things Considered to provide some perspective. Williams was formerly a senior trading floor executive and a bank examiner for the Federal Reserve Bank of Boston and San Francisco.