The final rules will also improve the processing of institutional trades, says the SEC, by requiring a broker-dealer to either enter into written agreements or establish, maintain, and enforce written policies and procedures "reasonably designed to ensure the completion of allocations, confirmations, and affirmations as soon as technologically practicable and no later than the end of trade date".
SEC chair Gary Gensler says: “Today’s adoption addresses one of the four areas the staff recommended the Commission address in response to the meme stock events of 2021. Taken together, these amendments will make our market plumbing more resilient, timely, orderly, and efficient.”
https://www.finextra.com/newsarticle/41810/sec-finalises-rules-for-move-to-t1