The 1934 Act is the backbone of the rest of this glossary. It created the sec, required brokers and exchanges to register, mandated ongoing reporting by public companies through form-10-k and form-8-k, and authorised the rules on margin credit administered by the federal-reserve.
Its most-cited provision is Section 10(b) and the rule written under it, rule-10b-5, which prohibits fraud in connection with the purchase or sale of any security and underpins insider-trading and market-manipulation enforcement.
Ownership transparency also comes from here: schedule-13d and schedule-13g for large stakes, section-16-insider reporting for officers, directors and 10% holders, and the tender offer rules.
Related: securities-act-1933, rule-10b-5, schedule-13d, section-16-insider, sec