Two banks can't agree on fourth-grade math | Alex Elliott

Patrick McKenzie (@patio11) is joined by Alex Elliott (@alexpotato), who has spent his career in SRE and operations roles at financial firms ranging from ten-person fintechs to global investment banks, to discuss what the back office actually does all day. They cover the life cycle of a trade: execution, clearing, settlement, and the constant reconciliation between counterparties who don't quite agree on what happened. Alex recounts the Friday afternoon when twenty million shares went out to the street instead of five, and Patrick explains what happens between 4:15 and 4:30 when one bank owes another $36 million and the person who owns that process is on vacation.

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Full transcript available here: https://www.complexsystemspodcast.com/two-banks-cant-agree-on-fourth-grade-math/

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Links:

• Alex’s website: https://alexpotato.com/

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Timestamps:

(00:00) Intro
(01:48) The life cycle of a trade
(04:37) Why you don't know who you traded with
(06:01) Hiding a large block trade
(10:04) Information walls inside financial firms
(12:49) What the middle office does: managing positions
(15:41) Calendars, time zones, and other sources of gibbering madness
(19:37) War story: twenty million shares out the door
(22:45) Sponsors: Mercury | Granola
(25:50) Ops as an iterated game
(28:53) Busting trades and who has the authority
(33:38) Sponsor: MongoDB
(34:29) Inside the Knight Capital collapse
(35:49) Agreements, obligations, and who you have to call
(36:57) Reconciliation, FTP files, and the humans behind them
(39:16) Deadlines, cutoffs, and the $36 million phone call
(44:26) How two banks fail to agree on fourth-grade math
(48:54) When the golden record goes down
(51:55) Finding the one person who can sell the position
(54:09) How much business do we do with Fidelity?
(56:38) Prime brokerage and extending credit
(01:01:03) Smart flow, dumb flow, and payment for order flow
(01:02:45) Wrap