A history of the TAD concept as it was originally developed and contemplated by the SEC. This repo is anchored in direct historical sources and open to outside contributions. It should keep a neutral viewpoint, simply describing how the original documents framed out the TAD concept rather than discussing modern applications beyond the past records.
timeline
1968 : Start of NYSE Central Certificate Service
Late 1971 : BASIC study commences
1973 : Jan 1 — NYSE moves CCS operations and assets to CCS Inc.
: May 11 — CCS Inc. transfers operations and $2.183m in net assets to DTC for 18,500 shares
: Jul 11–12 — Senate hearings on clearing agencies and transfer agents
2025 : NYSE subsidiary Stock Clearing Corporation holds all 10,000 DTCC Series A preferred shares