Please answer the above with an explanation/breakdown

What is the FASB's rationale for requiring: 1) reporting investments in frequently traded securities at market value instead of cost? 2) reporting held-to-maturity securities at the amortized cost instead of market value? 3) reporting investments using the equity method when the investors have significant influence on the dividend policy of the investees (e.g. holding 35\% of investees' outstanding shares)