🐘 Stock Market Elephant/The Pro Desk
The pro desk · deep research

How the pros actually do it

Sep 11, 2026 · Two Sigma, Renaissance, AQR, Jane Street, Man AHL, Millennium — sourced, tagged, and compared against our own process

We spent this series building a strategy factory in public. A fair question: is our process anything like what a professional quant desk does — or a hobbyist cosplay of one? So we did the research properly: primary sources where they exist (firms' own publications, researcher podcasts, published papers), books where they don't, and honest tags where the truth is folklore. Every claim below carries its confidence level, because a page about research discipline should practice some.

1 · The assembly line every serious firm runs

The clearest published blueprint is López de Prado's "meta-strategy paradigm": a quant firm's real product is not any strategy — it's the process that manufactures strategies, staffed as specialized stations. His claim: "every successful quantitative firm I am aware of applies the meta-strategy paradigm."

The research factory (López de Prado's meta-strategy: the firm's product is the process)DATACURATORSpoint-in-time truth,bias-free, cleanedFEATUREANALYSTSwhat predicts?catalog, not strategiesSTRATEGISTSeconomic theory→ specificationBACKTESTERSindependent judges,count every trialDEPLOYMENTproduction code,execution, latencyOVERSIGHTincubate → allocate→ monitor → retireThe wall that matters: strategists never grade their own homework.Backtesters know how many trials were run and report the odds the result is luck — and iteration against the test set is forbidden.Every firm implements some version: Man AHL as pre-specified research DAGs · Renaissance as one shared model withweekly all-hands challenge · Two Sigma as "hypothesis → measure → learn" with 10,000+ curated datasets · Jane Streetby deliberately blurring trader/researcher/engineer so no station becomes a silo. The pattern is the same: separate theperson who wants the strategy to work from the person who decides whether it does.
The station that defines professionalism is the red one: an independent backtesting function that knows how many things you tried and won't let you iterate against the test set.

2 · Same factory, very different philosophies

Where firms differ is upstream — where ideas come from — and at the top — how survival is governed:

← data-first (find it, then explain it)theory-first (explain it, then find it) → onebook ↑pods ↓RenaissanceWorldQuantTwo SigmaD.E. ShawAQRJane StreetMan AHLCitadel GQSMillenniumPositions from published philosophy and credible reporting (see sources) — placement is editorial, not the firms' own claim.Our little operation sits top-right-ish: hypothesis-registered, one shared book, one (human) risk-taker.
Renaissance found patterns first and demanded explanations second (unexplained signals traded at capped size). Two Sigma's literal tagline is "it starts with a hypothesis." AQR won't touch a signal without an economic story. Millennium barely inspects the research at all — it governs outcomes.
−2.5%informal talk begins−5%capital cut in half−7.5%terminatedMillennium-style pod governance (practitioner-reported): survival is a drawdown rule, not a research review.

3 · The statistical gates the field prescribes

The published methodology converges on a short list of hard gates — most of them born from the embarrassing discovery that with enough trials, pure noise produces beautiful backtests (about 14 independent tries manufactures an in-sample Sharpe of 1.0 from nothing):

gateprescriptionsource
significancet > 3.0, not the classical 2.0 — the field has run too many testsHarvey, Liu & Zhu, RFS 2016
Sharpe haircutas a first cut, halve the backtest Sharpe; formally, a multiple-testing haircut that hits marginal strategies hardestHarvey & Liu, JPM 2014/2015
deflated SharpeDSR > 95% vs the Sharpe pure luck would produce given N trialsBailey & López de Prado, JPM 2014
overfit probabilityPBO: odds the in-sample winner ranks below median out-of-sample; want single digitsBailey, Borwein, LdP, Zhu 2017
trial disclosurea backtest reported without its trial count is voidNotices of the AMS 2014
test designpurged CV with embargo; CPCV for a distribution of paths; walk-forward alone insufficientAFML ch. 7/12
backtest lengthmust grow with trials: ~5 years supports at most ~45 independent configsNotices of the AMS 2014
cost gateexpected costs ≤ ⅓ of pre-cost Sharpe, checked before evaluating the backtestCarver, Systematic Trading 2015
sizingvolatility targeting; forecasts capped; half-Kelly at mostCarver 2015; Chan
believabilitypersistent · pervasive · robust · investable · intuitiveAQR/Ilmanen; Berkin & Swedroe

And on transaction costs, one number worth framing: AQR published the analysis of $1.7 trillion of its own live executions — median cost ~6 bps on US large caps — because they consider the cost model important enough to be research in its own right.

4 · Edges rot — the pros plan for it

McLean & Pontiff 2016 — post-publication−58%CFM (Falck et al.) 2022 — 72 strategies, post-pub−43%McLean & Pontiff — merely out-of-sample−26%How much of a published strategy's Sharpe survives contact with the future — measured on hundreds of academicstrategies. Institutional buys' alpha decays to ~zero within 12 months (Di Mascio et al.). Edges are perishable goods.
Published decay measurements. This is why the factory never stops: a firm needs a pipeline of new edges just to stand still, and pre-set retirement criteria so dead strategies don't quietly bleed.

5 · The honest audit: our process vs theirs

Here is our actual pipeline — the one that produced one champion and nineteen graveyard entries — with every gate drawn:

GRAVEYARD19 ideasIDEAa question, a chart, a book, a readerPRE-REGISTERfamily + grid + expected verdict written down firstDATA QC GATEcoverage · thin days · volume · roll gapsONE ENGINEbacktester and live bot share every decision (1,324/1,324 parity)CPCV · PBO · DSR5 out-of-sample paths must agree · PBO < 20%STRESSslippage ladder · recent window · 1-minute resolutionRED REVIEWadversarial audit hunting bugs in our favorPAPERincubation vs the champion, no capitalLIVEhuman clicks every trade — nothing arms itself
Every red gate has fed the graveyard. The paper stage is next (pending broker API access); live is human-gated by design.

Scoring ourselves against the canonical lifecycle, stage by stage, no grade inflation:

canonical stageusthe honest note
economic hypothesis firstPARTIALwe write expectations down pre-test, but some families were pattern-first (crude's short bias is a regime bet we flagged, not a theory)
pre-registration + trial logSTRONGgrids declared in committed code before results; 19 negatives logged with evidence; this is our best subject
data curation as a disciplineSTRONGlearned the hard way: a calendar-roll artifact voided a verdict, so every cache now passes an automated QC gate
feature research before backtestsDIVERGESAFML says "backtesting is not a research tool; feature importance is" — we are backtest-first; tried meta-labeling once, dropped it
cost/capacity gate before evaluationPARTIALreal costs are baked into the engine from bar one, but as an input, not a pre-rejection gate; capacity is moot at micro size
independent backtest adjudicationPARTIALthe strategist and backtester are the same entity here — mitigated by frozen certification scripts, pre-committed verdicts, and adversarial red-team audits that have twice found bugs in our own favor
multiple-testing adjudicationSTRONGCPCV, PBO, deflated Sharpe with effective-trial clustering — the exact published machinery, reproducible from committed scripts
measurement resolutionSTRONGour bar-size rule (finale) is a lesson some of the literature doesn't even state explicitly
risk overlay / sizingSTRONGvol-scaled sizing certified at DSR 98%; ratchets clamped; the eval math published honestly
portfolio constructionTHINone certified strategy; the uncorrelated-second-signal search is recorded but the seat is empty
incubation / paperPENDINGdesigned (champion vs adaptive A/B) but blocked on broker API access — the pros would not skip this and neither will we
monitoring / decay / retirementPARTIALnightly regression re-certifies the champion on fresh data; live decay tracking doesn't exist yet because live doesn't exist yet
research cultureSTRONGthe graveyard IS the product; negative results are first-class citizens; audits attack our own conclusions
The verdict: on statistical discipline we run the published institutional playbook almost verbatim — because we took it from the same books their researchers wrote. What we cannot replicate is separation: ten thousand datasets, a trillion dollars of execution data to calibrate costs, and above all, an independent human whose job is to kill our favorite idea. Our substitute is process: frozen scripts, pre-registration, and adversarial review. The finale showed that substitute working — and the graveyard shows it working nineteen times.

6 · What we're stealing next

Three institutional practices this research convinced us to adopt, in order:

1. The cost gate, moved to the front. Carver rejects a strategy whose trading costs exceed a third of its pre-cost Sharpe before looking at any backtest. Our RT Levels v1 — 3,000 trades of costs against a thin edge — would have been flagged at the door.

2. Feature research as the discovery tool. Our order-flow dataset has only ever been tested as a bolt-on filter. The AFML prescription is to ask what the features predict under leakage-proof CV first, and only then build strategies from what survives.

3. Pre-set retirement criteria. Before the champion trades live, we will write down — in advance, like everything else — the live-vs-backtest divergence that forces a size-down and the one that forces retirement. Renaissance let validated models run "without interference"; Millennium fires on a number. Both work because the rule predates the drawdown.

Sourcing: Two Sigma (twosigma.com articles, careers/AlphaStudio), Jane Street "Signals & Threads" episodes (Cho; Mannes), Man AHL/Man Institute (Backtesting; AlphaTrend; Arctic), AQR (Craftsmanship Alpha; Frazzini-Israel-Moskowitz Trading Costs), Citadel GQS site, WorldQuant "101 Formulaic Alphas" (arXiv 1601.00991), Zuckerman "The Man Who Solved the Market", Narang "Inside the Black Box", Carver "Systematic Trading", López de Prado "Advances in Financial Machine Learning", Harvey-Liu-Zhu (RFS 2016; JPM 2014/15), Bailey-Borwein-LdP-Zhu (Notices of the AMS 2014; J. Comp. Finance 2017), Arnott-Harvey-Markowitz (JFDS 2019), McLean & Pontiff (JF 2016), Falck-Rej-Thesmar (Quant. Finance 2022), Di Mascio-Lines-Naik (SSRN). Pod-shop drawdown rules and incubation durations are practitioner-reported, not firm-official; firm placements on the quadrant are editorial. Nothing here is investment advice.