Transparency
Methodology
Every tool, benchmark, and quantitative article publishes its methodology. Assumptions, formulas, data sources, limitations, changelog — all open, all reproducible.
How we work
Open methodology, named limits
Source hierarchy. Peer-reviewed research and official exchange / regulator documentation come first. Vendor whitepapers and named-author technical writing come next, used for product behaviour they themselves authored. Public benchmark datasets (HumanEval, GSM8K, BIG-Bench, etc.) are cited where the benchmark's own publication is the primary source. Our own measurements come last and are flagged as such — never blended into a claim that reads as third-party evidence.
Open methodology, named limits. Every tool's formulas, coefficients, and modelling choices are published on its methodology page, dated, and linked from the tool itself. Where a formula has a domain of applicability — Kelly assumes stationary edge, Black-Scholes assumes log-normal returns, Sharpe ignores tail risk — the page says so before it shows the number.
Reproducibility. Tools run client-side. Given the same inputs you provide, the same numbers come out — there is no server-side weighting, no vendor-supplied parameter we hide, no opaque model. Methodology pages document the formulas in enough detail to recompute results in a spreadsheet or notebook.
Update cadence. Vendor pricing and rate-card data are refreshed on a quarterly cycle, with the last-refreshed date stamped on the page. Formula derivations are dated at first publication and re-dated whenever the derivation or coefficients change. Material changes are listed in the changelog section of each methodology page.
Corrections. When we get a number wrong we fix it inline, bump the article's Last updated timestamp, and log a dated entry at /corrections/. Material corrections carry a banner on the affected page for 30 days. Full editorial policy at /editorial-standards/.
Every page contains
Scope
What the tool / benchmark measures — and what it does not.
Algorithm
Formulas or procedures with primary-source citations.
Assumptions
Explicit list of every modeling choice.
Data sources
Primary sources, retrieval dates, licensing.
Reproducibility
Steps to run the same calculation on other data.
Limitations
Documented weaknesses, edge cases, caveats.
References
Peer-reviewed papers and authoritative texts.
Changelog
Dated history of methodology changes.
Calculators
Formulas, moments, closed-form solutions · 16 pages
Fractional Kelly Sizer
Map conviction tiers to fractional Kelly bet sizes with a drawdown Monte Carlo simulator. Client-side. Private by default.
Backtest Overfitting Score
Upload a backtest trade log and compute Probability of Backtest Overfitting (PBO), Deflated Sharpe Ratio, and the odds your edge survives live trading.
Token-Cost Optimizer
Compute the dollar cost of a trading research loop across Claude, GPT, and Gemini. Prompt length × model × retry × call volume → cost per idea and per.
Risk-Adjusted Returns Calculator
Paste a returns CSV. Sharpe, Sortino, Calmar, Omega, alpha, beta, tracking error, information ratio, max drawdown, and tail moments — plus.
Correlation Matrix Visualizer
Paste a multi-asset returns CSV. See the Pearson correlation heatmap, condition number, average absolute correlation, and eigenvalue concentration.
Returns Distribution Analyzer
Paste a returns CSV. Histogram, normal-overlay, QQ plot, skewness, excess kurtosis, Jarque-Bera test, tail-weight index. See why Sharpe alone misleads.
Efficient Frontier Builder
Paste a multi-asset returns CSV. See the Markowitz mean-variance frontier, the minimum-variance portfolio, the max-Sharpe (tangency) portfolio.
Financial Document Token Estimator
Paste a 10-K, 10-Q, 8-K or earnings transcript and see token count + one-pass extraction cost across eight frontier LLMs, with cache-hit toggle.
Agent Cost Envelope Calculator
Model an LLM research loop end-to-end — steps, tool calls, convergence checks, markets per day — and see per-loop, daily, and monthly cost with cost-cap.
Batch vs Real-Time Cost Calculator
Jobs per day, tokens per job, model, deadline — get real-time vs batch cost side-by-side with savings estimate and batch-eligibility flag. Based.
Deflated Sharpe Ratio Calculator
Bailey & López de Prado deflated Sharpe — corrects observed Sharpe for selection bias across K trials. Reports deflated Sharpe, PSR (probability of skill).
Earnings-Call Summarization Cost Calculator
LLM cost per stock per quarter to summarize earnings transcripts across Sonnet, Opus, GPT-5.5, Gemini 2.5 Pro/Flash. Cache-hit-rate aware. Snapshot pricing.
Sharpe vs Sortino Calculator
Paste daily returns; get Sharpe, Sortino, Calmar, and Omega side-by-side with a recommendation on which ratio fits your distribution.
Statistical Arbitrage Capacity Calculator
Maximum strategy AUM from signal half-life, daily volume, slippage, fees, and target Sharpe. Square-root impact closed-form.
Position Sizing under Edge Variance
Bayesian-Kelly bet sizing when your edge is itself uncertain. Compare deterministic Kelly, Bayesian-adjusted, and conservative lower-bound versions.
Drawdown-Recovery Markov Simulator
Time to recover from an N% drawdown given monthly Sharpe + skew + kurtosis. Cornish-Fisher Monte Carlo, percentile distribution of recovery months.
Comparators
Ranking methodology + scoring rules · 5 pages
Data-Vendor TCO Calculator
Compute annual cost of market data across Databento, Polygon, Alpaca, Tiingo, FMP, and Alpha Vantage for your exact universe, bar resolution, history.
Kalshi vs Polymarket Arb Scanner
Daily-refreshed scan of arbitrage candidates across Kalshi and Polymarket. Paired contract matching, tax + resolution-risk overlay, no signup. Edge data.
Broker API Comparator
Alpaca vs IBKR vs Tradier vs Schwab vs Robinhood — compare auth, rate limits, order types, market data, MCP, and fees before wiring a line of code.
Model Selector for Finance
Input task, latency budget, cost budget, context size, and quality sensitivity; get ranked model recommendations with rationale — grounded in published.
FTC vs FCA vs MiCA+DORA Regulatory Cost
Compare US (FTC), UK (FCA), and EU (MiCA + DORA) compliance cost for an AI-finance product. Snapshot data with as-of date — not legal advice.
Playgrounds
Algorithms, heuristics, attack corpora · 19 pages
Agent Skill Tester for Markets
Paste a SKILL.md definition + sample input + your Anthropic API key. See structured extraction, token cost, and latency — all in your browser. No signup.
Prompt Regression Tester
Run the same prompt against multiple models (Claude 4.5/4.6/4.7, GPT-5, Gemini 2.5) with your own keys. Diff outputs, score drift, catch regressions.
Hallucination Detector
Paste a source document + an LLM's extraction. Every numeric claim in the output is checked against the source. Client-side. Catches silent fabrication.
Order Book Replay Visualizer
Drop a Level-2 CSV and watch the book reconstruct tick by tick. Animated depth bars, best bid/ask, spread over time. Understand microstructure before.
Calibration Dojo
Train your probabilistic intuition. Answer binary forecasting questions at any confidence level; track Brier score and reliability curve over time. All.
Walk-Forward Validator
Upload a returns CSV. Rolling or expanding IS/OOS windows, per-window Sharpe, walk-forward efficiency, and a concatenated OOS equity curve. Catches regime.
Options Greeks Explorer
Black-Scholes pricer + live Greeks visualizer. Drag spot, strike, vol, DTE, rate, dividend yield — see delta, gamma, theta, vega, rho update.
Price-Blind Research Auditor
Paste a research prompt or agent context bundle. The auditor flags price numbers, directional words, and outcome-leaking phrases that cause LLMs.
Prompt Injection Tester
Red-team a finance agent against 24 documented prompt-injection attacks — direct override, role confusion, indirect injection via retrieved content.
Options Payoff Builder
Build 1–4 leg option strategies. Pick call/put, long/short, strike, and contracts. See the at-expiry payoff diagram, break-even points, maximum profit.
Pair Trading Cointegration Tester
Paste two price series. Engle-Granger cointegration test: OLS hedge ratio, Augmented Dickey-Fuller on residuals, Ornstein-Uhlenbeck half-life, z-score.
Execution Simulator
Model realistic order fills — square-root market impact, linear temporary impact, latency jitter, partial fills, and queue position. See the real cost.
Structured Schema Validator for Finance
Paste LLM JSON output and validate against four pre-built finance schemas — research output, trade decision, risk snapshot, peer comparison — with sanity.
Fallback Chain Simulator
Define a provider fallback chain, simulate rate-limit and latency failures, and see p50/p95/p99 latency, success rate, total cost, and degradation-event.
Forecast Scoring Sandbox
Paste a forecast stream (probability + outcome) and see Brier score with full decomposition, log loss, reliability diagram, and bootstrap confidence.
Walk-Forward Validation Visualizer
Paste a strategy returns CSV, get per-window in-sample vs out-of-sample Sharpe and the IS→OOS drop. Rolling and anchored window modes. Browser-only.
Cointegration Half-Life Solver
Engle-Granger residual ADF + Ornstein-Uhlenbeck half-life from any two price/return series. Hedge ratio, p-value, spread chart. Browser-only.
VaR Backtest — Kupiec & Christoffersen
Paste P&L + VaR series and run Kupiec POF, Christoffersen independence, and joint conditional-coverage tests. Likelihood-ratio χ² p-values.
LLM Finance Error Taxonomy
12 documented LLM-on-finance failure modes (hallucinated ticker, stale price, units, currency, off-by-100, fictional source, more). Paste output, see flags.
Generators
Schema contracts + assumption lists · 4 pages
Trading System Blueprinter
Pick your data source, LLM, broker, storage, risk engine, and logger. Get a Mermaid architecture diagram, a starter repo scaffold (ZIP), and a list.
Synthetic Market Data Generator
Generate synthetic price series — geometric Brownian motion, GARCH(1,1) with volatility clustering, regime-switching bull/bear, or copula-linked.
SEC Filing Chunk Optimizer
Pick a filing archetype, tune chunk size and overlap, and see chunk count, embedding cost, and structural-boundary warnings across three chunking strategies.
Quant Interview Question Generator
Curated bank of probability, stats, derivatives, microstructure, and regression questions across easy/medium/hard difficulty. Reproducible by seed. No AI.
Directories
Curation criteria + scoring scales · 1 page