BlackBird Financial's Judah Spinner on Investing, Discipline, and Philanthropy

According to Spinner, it is madness for an investor buying stock to have anything other than the operating realities of the underlying business in mind. I think of a stock only as a fractional interest in a business and always begin by asking myself: "How much would I pay for all of this company? And on that basis, what will I pay for 0.1% of it?"