LEON

COEFFECT / JOURNAL

Markets. Machines.
The city after hours.

Latest edition · 23 October 2026

The reading room

The archive.

47 complete daily editions. 739 notes. A record of the ideas, discoveries and stories worth keeping.

These are historical editions, presented with their original dates. Prices, odds, forecasts and event information are preserved as reported at the time.

October 2026

23 editions

Friday

23 October 2026

14 notes · 16 min read

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Multistrategy funds are growing beyond their own payrolls · METR's audit asks whether the monitor receives the work · Google makes Confidential G4 available, with attestation before sensitive data release

See all 14 notes

Thursday

22 October 2026

10 notes · 8 min read

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Balyasny recruits another Citadel equities manager · G-Research examines a storage format built for the way models actually read · Correct final numbers can conceal the wrong agent process

See all 10 notes

Wednesday

21 October 2026

13 notes · 9 min read

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The monitor is part of the system · Microsoft proposes a control plane for the “agentic insider” · Citadel’s boundary: assistance without surrendering judgment

See all 13 notes

Tuesday

20 October 2026

14 notes · 10 min read

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The lead: Jane Street's AI agents need identities, budgets and colleagues willing to say no · Balyasny moves an AI research leader into fundamental equities · Optiver recruits a Rokos partner to lead quant modelling

See all 14 notes

Monday

19 October 2026

29 notes · 11 min read

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HRT found the traffic the application logs missed · Millennium’s India operation passes 500 · A different Balyasny hire

See all 29 notes

Sunday

18 October 2026

22 notes · 10 min read

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Walleye’s expansion runs through other people’s funds · France’s bond stress has a collateral dimension · A loan can age more slowly than its collateral

See all 22 notes

Saturday

17 October 2026

15 notes · 9 min read

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A trade can matter even when its price doesn't change · UBS wants less of a seemingly attractive trade · A smaller fund's September reversal

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Friday

16 October 2026

26 notes · 6 min read

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Marex puts crypto carry into indices · A difficult week for stockpickers · Iskandar’s reported platform move

See all 26 notes

Thursday

15 October 2026

25 notes · 12 min read

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The tape: two kinds of AI finance · BlackRock wants to make compute investable · A smaller round lot changed the visible market

See all 25 notes

Wednesday

14 October 2026

22 notes · 7 min read

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The bank quarter is more uneven than the forecast · Asia's hedge-fund interest is showing up in target allocations, not just performance tables · A new listed derivative turns corporate KPIs into yes/no contracts

See all 22 notes

Tuesday

13 October 2026

17 notes · 12 min read

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The trading quarter banks have to defend · A capable model no longer needs one capable machine · The mathematics bottleneck becomes a queue

See all 17 notes

Monday

12 October 2026

19 notes · 10 min read

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The CFTC is drawing a perimeter, not blessing every prediction market · Prime brokerage has become too lucrative to treat concentration as somebody else's problem · Agent testing is still mostly testing the easy parts

See all 19 notes

Sunday

11 October 2026

17 notes · 8 min read

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The price of a bond crossed inside the same fund family · An AI trading study cannot resolve the small effect it cares about · StoreBench: an exploit changes the meaning of the score

See all 17 notes

Saturday

10 October 2026

18 notes · 6 min read

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The Liberty's season ends · A trading clock that deserves its own cost model · Listen: Quantedge

See all 18 notes

Friday

9 October 2026

12 notes · 6 min read

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Hedge funds are trading different Septembers · The IMF's crowding warning belongs in the portfolio meeting · An office agent is really a permissioned work graph

See all 12 notes

Thursday

8 October 2026

15 notes · 7 min read

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Hedge funds are not one trade right now · The gilt-repo argument is about where fragility lives · Tokenized markets arrive with a liquidity-clock problem

See all 15 notes

Wednesday

7 October 2026

20 notes · 8 min read

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September’s multistrategy tape · KKR buys the plumbing · The order book has a memory

See all 20 notes

Tuesday

6 October 2026

17 notes · 7 min read

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September rewarded structure more than swagger · The CFTC's perpetual-futures work is a perimeter story · Beam is a preview, not yet a downloadable open-weight fact

See all 17 notes

Monday

5 October 2026

14 notes · 9 min read

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Three more names on the trend scoreboard · Cboe moves the equity-options clock · Jane Street’s chip exposes a testing trap

See all 14 notes

Sunday

4 October 2026

16 notes · 8 min read

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AQR’s September tells three different stories · The prediction-market firms getting bigger · Polymarket US’s October 9 block-fee change

See all 16 notes

Saturday

3 October 2026

18 notes · 9 min read

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September funds: the new numbers · Systematic equity had a different September · Friday’s payroll report revises the summer

See all 18 notes

Friday

2 October 2026

20 notes · 9 min read

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September fund figures have started arriving · Taula’s concentrated rates fund lost 12.2% in September · Bridgewater’s AI-driven fund has a return to discuss

See all 20 notes

Thursday

1 October 2026

20 notes · 9 min read

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Ellington’s 500 possible rate paths · AQR: where the tax benefit actually comes from · A volatility hedge can fail while equities fall

See all 20 notes

September 2026

24 editions

Wednesday

30 September 2026

19 notes · 8 min read

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The market: the long end still sets the terms · Goldman’s private-credit outlier is partly an investor-base story · Metrics Credit is a different kind of stress

See all 19 notes

Tuesday

29 September 2026

18 notes · 10 min read

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Markets: the bond selloff has become the weather · A short fund is hunting private-credit borrowers in public markets · Prediction markets are rebuilding single-stock derivatives by another name

See all 18 notes

Monday

28 September 2026

12 notes · 9 min read

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Turkey’s fund run exposed a market-design trap · The Treasury basis trade is shrinking because both sides have less appetite · A coding benchmark finally tests reconstruction from behavior

See all 12 notes

Sunday

27 September 2026

17 notes · 10 min read

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Davidson Kempner buys into agricultural bank risk · Taula's September has been painful · L1's gold strategy deserves a look at the vehicle labels

See all 17 notes

Saturday

26 September 2026

17 notes · 8 min read

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AI credit has started to price the capex concentration · The borrowing is only the visible layer · MX2 is moving “professional customer” surveillance to a monthly clock

See all 17 notes

Friday

25 September 2026

12 notes · 8 min read

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SoftBank is converting the OpenAI bet into expensive public debt · Muse’s apparent autonomy currently contains people, permissions and a very large market reaction · An OpenAI research agent crossed an Australian government boundary

See all 12 notes

Thursday

24 September 2026

13 notes · 8 min read

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This morning: the Kurono ordering window · Banks are being asked what happened while Jane Street was losing $15 billion · Qatar and JPMorgan have created a $20 billion investment channel

See all 13 notes

Wednesday

23 September 2026

17 notes · 12 min read

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A crypto-arbitrage founder leaves for energy trading · Istanbul changes the index after the fund crisis · Snorkel’s revenue jump explains where frontier-model spending moved

See all 17 notes

Tuesday

22 September 2026

16 notes · 10 min read

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Endeavor’s merger price is now a courtroom input · Quadrature’s foundation now spends on the scale of a large fund · Grok 4.7’s most actionable launch detail is cache routing

See all 16 notes

Monday

21 September 2026

14 notes · 10 min read

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Jane Street’s July loss is becoming a test of the prime-broker map · The NSE is selling stock while its great growth engine slows · Revolut has built a bank that still lends like a visitor

See all 14 notes

Sunday

20 September 2026

34 notes · 22 min read

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Behind the signs in Queens — afternoon edition · A federal agent fills the Guggenheim — afternoon edition · Hommali: rice, smoke and two quite different rooms — afternoon edition

See all 34 notes

Saturday

19 September 2026

14 notes · 10 min read

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One millisecond brought six hours of air-traffic restrictions · Fund flows say caution; the sector ledger says selection · One volatility model, two probability measures

See all 14 notes

Friday

18 September 2026

14 notes · 9 min read

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The SEC opens an onchain annex to the stock market · The Bank of England divides its gilt portfolio into three jobs · OpenAI is entering legal work as infrastructure

See all 14 notes

Thursday

17 September 2026

14 notes · 11 min read

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A trading desk changes employers · Turkey’s fund run exposes the problem with a rising NAV · A voice agent small enough to inspect

See all 14 notes

Wednesday

16 September 2026

11 notes · 11 min read

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Bloomberg opens the whole FX-options RFQ to code · Nasdaq’s order-level self-match controls arrive today · An agent finds the assumption hidden inside a lint rule

See all 11 notes

Tuesday

15 September 2026

10 notes · 10 min read

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At noon ET: Artificial · Schonfeld has built a 45-pod macro business—and replaced nearly its entire first cast · The SEC caps the market-data reward for quoting without trading

See all 10 notes

Monday

14 September 2026

8 notes · 7 min read

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Zverev closes the door · Anthropic offers outsiders the right to publish · Eurex gives FX desks a reason to follow their collateral

See all 8 notes

Sunday

13 September 2026

8 notes · 8 min read

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Citadel is testing how many kinds of “equities” one risk system can contain · Nasdaq’s night session begins with a second control plane · Courtside—and a separate market decision

See all 8 notes

Saturday

12 September 2026

9 notes · 9 min read

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Situational Awareness’s second problem is who will finance the recovery · CME wants to remove the interval between the two legs · Courtside—and a separate betting decision

See all 9 notes

Friday

11 September 2026

9 notes · 10 min read

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ChatGPT for finance: the control plane matters more than the demo · The market-neutral scorecard says more about hedging than stock selection · Courtside

See all 9 notes

Thursday

10 September 2026

9 notes · 8 min read

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The valuable part of SIX’s new API is the permission slip · Prediction markets are acquiring the boring things institutions need · DeepSeek’s small release is unusually inspectable

See all 9 notes

Wednesday

9 September 2026

9 notes · 6 min read

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Astra has already become the verifier. · India’s close briefly became an 850-point opinion poll. · Cboe’s free backup port is really a control-design exercise.

See all 9 notes

Tuesday

8 September 2026

11 notes · 6 min read

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Cboe is changing the auction clock—and withholding the interesting number. · Man’s useful AI story is the research graveyard. · NYSE American’s extended-hours approval has a small, consequential “or.”

See all 11 notes

Monday

7 September 2026

11 notes · 6 min read

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The less-obvious AI concentration is in credit. · August returns: the dispersion is more informative than “pods tread water.” · Six cents that belong in the options router.

See all 11 notes

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