Developer Blog

Technical guides for developers building on the StockFit API. XBRL parsing, point-in-time data, backtesting patterns, and SEC EDGAR engineering notes.

Revenue Segmentation API: Revenue by Geography and Product From SEC Filings
TutorialRevenue Segmentation APIRevenue by GeographyRevenue by ProductXBRLDimensional FactsSEC EDGAR

Revenue Segmentation API: Revenue by Geography and Product From SEC Filings

The StockFit Revenue Segmentation API returns revenue split by geography (countries, US states, regions, residuals) and by product, period by period, parsed from XBRL dimensional facts in 10-K, 10-Q, and 20-F filings.

June 6, 202612 min readStockFit Engineering
Company Peers API: Comparable Companies, Ranked, Done Right
ComparisonCompany Peers APIComparable CompaniesPeer AnalysisSFIC

Company Peers API: Comparable Companies, Ranked, Done Right

Most financial data APIs have no company peers endpoint, and the one that does returns a flat, often-empty ticker list. The StockFit Company Peers API returns up to 6 same-industry comparables, ranked by revenue, classified by our proprietary SFIC system.

May 29, 202611 min readStockFit Engineering
Executive Officers API and Executives API: A Developer Guide
TutorialExecutive Officers APIExecutives APICEO dataForm 4Section 16DEF 14ACorporate OfficersSEC API

Executive Officers API and Executives API: A Developer Guide

Get a company's current CEO and executive officers, with titles, from an API. How the StockFit Executive Officers API is built from SEC Form 3/4/5 insider filings, with real examples.

May 29, 202610 min readStockFit Engineering
StockFit ChatGPT App: Stock Fundamentals and SEC Filings Inside ChatGPT
AnnouncementChatGPT AppChatGPT Apps SDKMCPAI AgentsSEC EDGARStock Data

StockFit ChatGPT App: Stock Fundamentals and SEC Filings Inside ChatGPT

The StockFit app is live in ChatGPT. Add it, sign up free, and ask about earnings, financial statements, insider trades, and ETF holdings. Every answer comes from SEC EDGAR filings.

May 21, 20268 min readStockFit Engineering
Fundamental Stock Analysis Explained: What It's Used For and How Investors Actually Do It
AnalysisFundamental AnalysisStock ValuationInvestment ResearchFinancial StatementsSEC Filings

Fundamental Stock Analysis Explained: What It's Used For and How Investors Actually Do It

How professional and retail investors use fundamental stock analysis to value companies, screen stocks, and build conviction, plus the financial data inputs that power every step.

May 15, 202610 min readStockFit Engineering
Insider Cluster Buys: Do They Beat the S&P 500? 7-Year Test
AnalysisInsider Cluster BuysForm 4Insider TradingS&P 500BacktestingEvent Study

Insider Cluster Buys: Do They Beat the S&P 500? 7-Year Test

Three or more officers or directors buying in a 30-day window: does this insider buying signal beat the market? We tested 45 discretionary S&P 500 clusters from 2018 to 2024 against SPY using Form 4 data.

May 13, 202613 min readStockFit Engineering
Earnings Calendar API and Earnings API: A Developer Walkthrough
TutorialEarnings APIEarnings Calendar APIEPS8-K Item 2.02TutorialNVDA

Earnings Calendar API and Earnings API: A Developer Walkthrough

Every endpoint in the StockFit earnings API: the earnings calendar API (upcoming reports, batch lookup, single-ticker date), EPS history, snapshot, trends, growth, quality, and 8-K Item 2.02. Live NVDA JSON and cURL examples.

May 11, 202612 min readStockFit Engineering
Form 10-K Financial Statements (and Every Other SEC Filing We Read So You Don’t Have To)
ReferenceForm 10-KFinancial StatementsSEC EDGARSEC Forms13F8-KNPORT-PReference

Form 10-K Financial Statements (and Every Other SEC Filing We Read So You Don’t Have To)

Where the income statement, balance sheet, and cash flow statement actually live — plus 17 more SEC filings that power the StockFit API. What each form is for, what data we extract, and which endpoint serves it back to you.

May 9, 202612 min readStockFit Engineering
StockFit API vs. Alpha Vantage for Fundamentals
ComparisonComparisonFundamentalsAlpha VantageXBRLSEC EDGAR

StockFit API vs. Alpha Vantage for Fundamentals

Both speak JSON. One reads SEC filings. The other reads its own normalized table. A side-by-side look at standardized statements, raw XBRL, filings access, ownership, insider data, executive comp, ETFs, and pricing — with verifiable sources on both sides.

May 7, 202613 min readStockFit Engineering
A Deep Lens on Any ETF: From Free-Tier Profile to Forensic Analysis
TutorialETFFundsN-PORTN-CENTutorial

A Deep Lens on Any ETF: From Free-Tier Profile to Forensic Analysis

Walk SPY end-to-end with the StockFit fund endpoints. Start with /profile and /holdings on the entry tiers, then move into the N-PORT and N-CEN power tools (flows, changes, overlap, fund health, fee analysis, service providers) for a forensic view your brokerage page does not show. Live JSON, charts, and a composite playbook.

May 4, 202613 min readStockFit Engineering
The Holy Grail API for Stock Backtesting: Point-in-Time Fundamentals With a Full Amendment Audit Trail
TutorialBacktestingPoint-in-TimeLook-Ahead BiasQuantPIT DataAmendments

The Holy Grail API for Stock Backtesting: Point-in-Time Fundamentals With a Full Amendment Audit Trail

Look-ahead bias is the silent killer of quant backtests. StockFit is the only fundamentals API that ships a per-fact, per-amendment audit trail with `before` values, a true point-in-time ledger you can mathematically rewind. Available on every tier, including free.

April 30, 202613 min readStockFit Engineering
Sector & Industry-Specific Metrics: StockFit API vs. financialmodelingprep.com
ComparisonSector MetricsBankingInsuranceREITsComparison

Sector & Industry-Specific Metrics: StockFit API vs. financialmodelingprep.com

Why a single key-metrics shape silently fails for banks, insurers, and REITs — and how StockFit returns the right metrics for the right business model. With real responses, code examples, and a step-by-step screen.

April 22, 202614 min readStockFit Engineering
StockFit API vs. sec-api.io for Financial Data Conversion
ComparisonComparisonXBRLSEC APIInsider Trading

StockFit API vs. sec-api.io for Financial Data Conversion

How the two products approach XBRL-to-JSON conversion, insider trading data, and developer ergonomics. Verified facts on both sides, no vendor spin.

April 22, 202612 min readStockFit Engineering
Converting XBRL Financials to JSON for Backtesting
TutorialXBRLBacktestingSEC EDGARQuant

Converting XBRL Financials to JSON for Backtesting

Why SEC XBRL is hard to use directly, what "as-reported" really means, and how to assemble a clean point-in-time dataset for systematic strategies.

April 22, 202615 min readStockFit Engineering

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