Sounds more like embezzlement than fraud, but a key question will be what powers the CEO that don't require shareholder votes. For example, if an employee came to him and asked for 2 weeks of pay advance due to some emergency, could he grant it unilaterally? Obviously it's different since there's a conflict of interest when he's doing it for himself, but it's still a relevant data point. Check your bylaws to see if this sort of thing is spelled out.