15. There is a widespread use of Rule 10b-5-1 trading plans by officers and directors of public companies who regularly possess material nonpublic information but who want to buy or sell stock of their corporation at a time when they are not in possession of material nonpublic information. Usually, a 10b-5-1 trading plan is a contract between the insider and a broker. Why are these plans used by corporate insiders, such as officers and directors?