"Under SEC rules, companies can't buy back any of their shares during the roughly five-week period which ends two days after the company's results are released."
I've done a little more research on blackout periods and trading plans.
Except for very special circumstances, I couldn't find any SEC rules regarding blackout periods. Apparently the establishment of blackout periods, is a recommended procedure to protect corporate personnel from insider trading charges. The following is a good article on the subject:
In regard to trading plans the SEC in order to clarify and protect individuals and corporations from insider trading charges, came up with rules 10b5-1 and 10b-18 which basically sets up defenses against insider trading charges.
Rule 10b5-1 applies to trades by persons, businesses, or other type of organization, while 10b-18 applies to corporate stock repurchases. The rules call for setting up trading plans that have specific requirements, with the key requirement being that when the trading plans were established it was not “on the basis of” material nonpublic information. For more information on the background and requirements of rules 10b5-1 and 10b-18 see:
IDCC may, or may not have rules covering blackout periods and rules covering how employees, officers and directors may trade company stock, including the use of 10b5-1 trading plans. While some companies publicly disclose their rules, I haven’t found any IDCC references to any such rules.
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