One listing · Source code only Verified demo — run from the code Est. 2026 · Sold directly

Test the
backtest.

Before you trust the result.

An executable validation harness that recomputes predictive accuracy, tests it against baselines, walk-forward folds, leakage and calibration — then returns a verdict with an exit code.

$4,950 · one payment Via escrow first Source code only

buildit certify — vendor-model-sample.csv
buildit certify vendor-model-sample.csv
recompute (claimed column ignored)416 / 600
recomputed accuracy69.33 %
claimed accuracy in file78.00 % — ignored
baselines run5 · 5/5 beaten
walk-forward folds80.00 → 55.83
wilson 95 % interval65.5 – 72.9 %
leakage gatepassed
verdictOVERFIT · exit 1
OVERFIT 69.33% exit code 1 — gate: fail
earliest fold 80.00% → latest 55.83% recomputed in your browser
01 / Verified demo
69.33%
recomputed, not the 78.00% the file claimed
02 / Sample
600
raw predictions — accuracy recomputed from every one
03 / Verdict
OVERFIT
exit code 1 · gate fail — the tool does not grade on a curve
04 / Price
$4,950
one payment · escrow funded first · source code only
Free tool

Try the free Backtest Lie Detector — paste a prediction file, get a verdict.

Run it in your browser All free tools
Chapter 00 — Who this is for

Right buyer.
Right tool.

This is not a mass-market product. It is a specialised validation harness for teams who need to prove or disprove backtest claims before deploying capital.

Best for
  • Quant developers building internal validation tooling
  • Research teams auditing model claims before deployment
  • Technical founders acquiring a certification harness
  • Fund analysts who need reproducible backtest checks
  • Anyone who has been burned by a backtest that didn't hold up live
Not for
  • Expecting a profitable trading strategy or daily signals
  • Wanting a live brokerage with licensed market data
  • Needing production SaaS, hosting, or SLA support
  • Wanting live execution, checkout, or multi-user accounts
  • Looking for a "black box" that prints buy/sell signals
Chapter 01 — The problem

A good-looking
backtest is not proof.

Six things can make a validation result look excellent while saying nothing. Each one is met by a specific check inside the harness — if the file is honest, the check answers it; if it isn’t, the verdict comes back OVERFIT · exit 1.

A claimed number

“92% accurate” — according to whom?

A CSV with a claimed-accuracy column tells you what the vendor wrote. The predictions tell you what happened. Check 01 recomputes from raw predictions and ignores the claim.

No comparison

Beating what, exactly?

Accuracy means nothing until it beats the replies “up every day”, “no change”, and a momentum rule computed from the same data. Check 02 runs the baselines and never fakes the ones it can’t compute.

Hidden decay

One average hides the fall.

The demo folds from 80.00% down to 55.83% while the headline reads 69.33%. Check 03 measures fold by fold, from earliest to latest, so decay can’t average out of the story.

Tuned to win

One of 100 trials looks great. That’s the point.

Trying many configurations guarantees a lucky winner. Check 04 applies a Bonferroni correction on the trial count — the more you tried, the harder it is to pass.

Tomorrow’s answer

Predicting the past, using the future.

Leakage quietly slips information the model couldn’t have had into the test window. Check 06 gates it — either the columns pass or the run fails, whatever the headline says.

Small samples

A streak of 40 rounds up to a claim.

Forty predictions at 70% is not four thousand at 70%, and vendors count on nobody asking. Check 05 computes Wilson 95% intervals on every accuracy figure the file can produce.

Chapter 02 — The method

Eight validation components.
One verdict.

Feed it predictions. It does the rest — and the verdict comes with an exit code, so it can gate a pipeline instead of sitting in a report nobody reads.

  1. 1Ingestpredictions CSV parsed, unusable files rejected — never scored
  2. 2Recomputeaccuracy from raw predictions; claimed column ignored
  3. 3Baselinesup to 5 naive rules run on the same data
  4. 4Walk-forwardaccuracy measured fold by fold, earliest → latest
  5. 5StatisticsWilson intervals, Bonferroni on trial count
  6. 6Verdictexit 0 edge demonstrated · exit 1 fail or inconclusive · exit 2 input unreadable
01 Recompute, don’t trust Verdict gate · always runs

Accuracy is recomputed from raw predictions. Any claimed-accuracy column in the file is ignored. If the file says 92% and the predictions say otherwise, the predictions win. This is the check the whole harness is built around.

BoundaryIt can only recompute what the file contains. A file with no usable predictions is rejected, not scored.
02 Baselines that actually run Verdict gate · up to 5 baselines

The model is compared against baselines computed from the data supplied — not against a number someone wrote down. Five baselines are defined. The verified demo run measured all 5 and beat 5/5 (best baseline: momentum-5d at 51.00%). Without price history (e.g. --no-prices, or the market service unreachable) only 2 run: always-bullish and no-change — the other three are never faked.

BoundaryOnly 2 baselines can run without price history. The documented demo command loads price history via the repo’s market service, so all 5 ran.
03 Walk-forward consistency Verdict gate · period stability

Accuracy is measured fold by fold, earliest to latest, so decay shows up instead of hiding inside one average. This is period stability: how the model holds up across time periods. Purged walk-forward exists as a tested library function, but it is not a DIRECTION verdict gate. The distinction is stated here because buyers should not have to discover it later.

BoundaryPeriod stability is the gate. Purged walk-forward is a library function, not a verdict gate.
04 Multiple-testing correction Verdict gate · Bonferroni

Trying many configurations and reporting the best one is corrected for — the more you tried, the harder it is to pass. Bonferroni correction is applied to the number of configurations tried. That count is supplied with the run, so it is only as honest as the input — the harness does not pretend to know what it wasn’t told.

BoundaryThe trial count is an input, not a discovery. Garbage in, garbage out.
05 Uncertainty, stated plainly Wilson intervals · always runs

Every accuracy figure carries a Wilson interval, so a small sample can’t dress up as certainty. A 70% on 40 predictions and a 70% on 4,000 predictions are not the same claim, and the output doesn’t let them look like one.

BoundaryWilson intervals are computed from the sample supplied. They describe the sample, not the market.
06 Leakage gate Verdict gate · pass / fail

Checks for leakage — information in the test data that the model shouldn’t have had when it made the prediction. A model that “predicts” with tomorrow’s information fails here, however good its headline number looks.

BoundaryA pass means the supplied columns pass the gate. It is not a proof about unseen data.
07 Probability of backtest overfitting Not a gate · needs candidates file

When a candidates file is supplied, the harness estimates the probability that the chosen model only looks best because many were tried. For a single model with no candidates file, PBO is null — and never a gate. It answers one question: among everything you tried, how likely is this winner a fluke?

BoundaryNull for single models. Never a gate. Never invented.
08 Calibration Verdict gate · always runs

Checks whether the model’s stated confidence matches how often it is actually right. A model that says 90% and is right 60% of the time is miscalibrated — useful to know before its probabilities drive position size.

BoundaryCalibration needs a stated confidence. Without one there is nothing to compare.

What decay looks like

In the verified demo, the sample model starts at 80.00% and ends at 55.83%. The overall 69.33% hides the story. The folds tell it.

One average can flatter a model; a sequence cannot.

Walk-forward · 5 folds · verified demo −24.17 pts
Walk-forward accuracy falls from 80.00% to 55.83% across five folds Fold one 80.00%, fold two 77.50%, fold three 71.67%, fold four 61.67%, fold five 55.83%. Overall 69.33%. 80 70 60 50 F1 F2 F3 F4 F5 80.00 55.83
Earliest 80.00%Overall 69.33%Latest 55.83%416 / 600
All five folds shown in the chart above — exactly the numbers the demo returns. Page copy shows earliest, latest, and overall; the chart shows the full sequence.
Chapter 03 — The package

You buy the test.
The platform comes with it.

Two things transfer in one sale: the certifier itself, and the forecasting platform it was built against — as a reference implementation, not as a running business.

01 · The certifierthe harness

Runs with no database.
Predictions in, verdict out.

A CLI-shaped harness that returns a verdict and an exit code, so a bad backtest can fail a pipeline rather than a meeting.

  • Recomputed accuracy & Wilson intervals
  • Baselines from the data supplied — verified demo ran 5, beat 5/5
  • Walk-forward consistency, leakage gate & calibration
  • Bonferroni correction & PBO when a candidates file is supplied
  • Verdict with exit code to gate a pipeline
02 · The reference platformincluded

The forecasting platform
the harness was built against.

A Next.js platform included so the certifier can be seen in context — pages, routes, models and all. It is not a business in a box.

  • 73 pages · 102 API routes · 50 Prisma models
  • ~172,000 lines in src · 452 commits
  • Paper trading only — no live broker execution
  • Market data via unofficial Yahoo Finance — budget for a licensed feed
  • Single-operator build — no multi-user accounts, no checkout
Input
Predictions as a CSV. Any claimed-accuracy column is ignored.
Output
Recomputed accuracy, Wilson interval, verdict and an exit code — exit 1 means fail.
Baselines
Verified demo: 5 run, 5/5 beaten (best: momentum-5d 51.00%). Without price history only 2 run.
Database
None required for the certifier.
Walk-forward
Period stability across folds. Purged walk-forward is a tested library function, not a verdict gate.
PBO
Needs a candidates file. Null for single models, and never a gate.
Platform
73 pages · 102 routes · 50 models · ~172,000 lines · 452 commits.
Setup
3–5 engineer-days. Node 22 (the repo’s CI pins Node 22).
Running costs
$35–80 / month at hobby scale. Model weights: Chronos-2 (Apache-2.0, ~464 MB) downloads from Hugging Face at first run; TimesFM 3.0 (~1.32 GB, non-commercial) ships in models/.
Chapter 04 — The evidence

Reproduce it
before you pay.

Every number on this page traces to one command over one fixture. Run it in the acquired repo — if the harness doesn’t return this verdict, don’t buy the tool.

demo fixture · vendor-model-sample.csv Node 22
npx tsx scripts/certify-model.ts examples/vendor-model-sample.csv --configurations 20
expect recomputed 69.33% · wilson 65.5–72.9% · baselines 5/5 beaten · OVERFIT · exit code 1
sha256 79efd015a8501d1fa7ba79931532f5683b4c0e5f9bb56263d2544a8877cb3bac
Chapter 05 — Read first

Read this before
you enquire.

This section is the sale. If any of it is a problem, it should be a problem now — not after escrow.

01

$0 revenue. 0 users.

Pre-launch. No customers, no accounts, no domain, no brand to inherit. There is nothing to “take over” — only code to own.

02

Our own forecaster is a coin flip.

It measured ~49.7% directional accuracy at n = 1,160. You are buying the tool that proves that — not a predictive edge.

03

Never run in production.

No uptime history, no live broker execution, no licensed market-data feed included. The platform has never served a real user.

04

Narrower than a headline.

Without price history a run is capped at 2 baselines, not 5 (the verified demo ran all 5 and beat 5/5). Walk-forward here is period stability, not purged out-of-sample training. PBO is null for single models. Purged walk-forward and deflated Sharpe are tested library functions, not verdict gates.

05

Substantially AI-assisted.

Development used AI coding tools extensively. Copyright in purely AI-generated expression is unsettled, and that is disclosed in writing to buyers.

06

It was briefly public under MIT.

The repository was public under an MIT licence from 1–22 October 2026. Anyone who copied it then holds a perpetual MIT licence to that snapshot. Exclusivity cannot be warranted, and the sale does not claim otherwise.

Nothing on this page is a footnote to be discovered later. The limits above are the offer, in full.

Read the terms
Chapter 06 — The deal

One payment. Escrow first.
No surprises after.

The sequence is fixed. Money is secured before code moves — for both sides.

Asking price
$4,950
USD · one payment · full source code— escrow first, transfer second.
  • Included — the certifier harness and the reference platform, both repos transfer
  • Complete source — ~172,000 lines · 452 commits, at the agreed commit
  • One in-scope support window — 7–14 days of technical questions after transfer
  • Not included — a strategy, customers, licensed market data, or a post-sale SLA
Escrow funded

The buyer funds escrow for the full $4,950. Nothing moves before this.

Repo transferred

Full repository transfer at the agreed commit, as a squashed snapshot.

Buyer confirms

The buyer checks what was received against these terms.

Escrow releases

Funds release only after confirmation. No repo access before escrow funds.

Price
$4,950 USD, one payment only. No instalments, no revenue share, no earn-out.
Escrow fee
Paid by the buyer, or deducted from the proceeds at close.
Handover
7–14 days of questions only. No SLA, no maintenance, no future updates.
Proof pack
A free short summary is available to anyone on request. The full proof pack is shared privately, only after screening, under an evaluation-only licence — no commercial use or redistribution.
What’s not included
No customers, no accounts, no API keys, no .env file, no licensed data feed. The buyer supplies their own keys and database.
Condition
Sold as-is. Liability is capped at the sale price. Full written terms are provided before any payment.
Chapter 07 — The seller

One builder.
No intermediaries.

A direct conversation with the person who built the tool — no sales team, no broker, no marketplace cut.

Dron Pancholi · builder & seller

Dron Pancholi

Builder of BuildIT Index · Seller, directly

BuildIT is Dron Pancholi’s project, and this sale is direct: the person who built the harness is the person who answers your questions and hands over the code.

That is deliberate. A certification tool is only worth what its maker will stand behind in the open — including the limits listed above.

No agency, no broker, no marketplace cut layered on top. The terms on this page are the terms.

Direct saleNo brokerSold as-is
Chapter 08 — Questions

Before you ask,
the answers.

The questions a diligent buyer asks first — answered here, in the same words as the terms above, so nothing changes between this page and the paperwork.

01What exactly am I buying?

The source code only: the certification harness plus the forecasting platform it was built against, as a reference implementation. No customers, no accounts, no API keys, no .env file and no licensed data feed are included.

02How does the sale work?

The buyer funds escrow for the full $4,950 first. The repository is then transferred as a squashed snapshot, the buyer confirms what was received, and escrow releases. No repo access is given before escrow funds.

03What support is included after the sale?

7–14 days of questions only. No SLA, no maintenance and no future updates. The escrow fee is paid by the buyer or deducted from the proceeds at close.

04Was this code ever public?

Yes. The repository was public under an MIT licence from 1–22 October 2026. Anyone who copied it then holds a perpetual MIT licence to that snapshot, so exclusivity cannot be warranted.

05How hard is it to run?

Setup is 3–5 engineer-days on Node 22 (the repo’s CI pins Node 22), running costs are $35–80 per month at hobby scale, and the Chronos-2 weights (~464 MB, Apache-2.0) download from Hugging Face at first run.

06Can I see proof before paying?

A free short summary is available to anyone on request. The full proof pack is shared privately, only after screening, under an evaluation-only licence with no commercial use or redistribution.

07Is BuildIT’s own forecaster any good?

It measured about 49.7% directional accuracy at n = 1,160 — a coin flip. You are buying the tool that proves that, not a predictive edge.

Chapter 09 — Enquire

Start with a question,
not a payment.

A free short summary first if you want it. Serious buyers get the full proof pack after screening — nothing is sold on a first email.

Choose what you’d like, add a line about yourself if you wish, and send the enquiry.

Every enquiry is read by Dron directly. Ask for the demo, the summary, or the full terms — before anything is discussed about price, the facts on this page are the starting point.

  • 01No repo access is given before escrow funds.
  • 02The full proof pack is shared only after screening.
  • 03Asking for the free short summary commits you to nothing.
$4,950 · escrow read by Dron
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