| May 1988 | An extensive NASD investigation begins into SOES trading. |
| August 1988 | The first significant NASD amendment to the SOES rules is made. It has the effect of reducing SOES orders by redefining split orders to include trades done on a discretionary basis; this rule is interpreted by the NASD to include all trades flowing from a ''single investment decision" occurring within a 5-minute period. Also, the NASD enacts a restrictive definition of professional trader and adopts the rule prohibiting the use of SOES for a host of customers who were related to the firm's principals including in-laws (the relative rule), each of which was designed to make SOES trading more difficult. |
| October 1991 | The NASD enacts the another group of major modifications to the SOES rules. |
| 1. | The NASD expands the professional trading account rules to include any transaction in which SOES is used on any one side of the buy or sell transaction. |
| 2. | The NASD adds subjective factors to be considered in determining professional trading account status. |
| 1993 | The NASD rescinds the new professional trading account conditions after I sue the SEC in the U.S. Court of Appeals to contest the rules. The court suggests those rules are overly burdensome and vague in the Timpinaro v. SEC case. |
| 1993 | 1. | The NASD proposes new Interim SOES Rules until the NASD's proposed N*PROVE System is approved by the SEC. The N*PROVE System, designed by the market makers to replace the SOES automatic execution system, is an inferior order delivery system affording the market makers 20 seconds in which to decide whether to honor their quotes. |