The field manual of free market tools.
An open directory of free and community-built market tools — screeners, calculators, data feeds — cataloged like a spec sheet.
- UNITS
- 16
- SURPLUS
- 8
- PAY-TO-RANK
- NONE
- LICENSE FILTER
- FREE/OSS
SO-01
Only free or open-source tools
SO-02
Spec-sheet listings: platform, license, update cadence
SO-03
Community submissions, editorial review
SO-04
No pay-to-rank
Unit index
FULL MANIFEST →FILL MODEL
Realistic mid + slip
OPTIONS
Full chain
API
Public REST + WS
COST
$0 forever
Reference free paper-trading unit. Options, fills, and live quotes without depositing cash.
Supply lines
Latest dispatches
2026-09-29
Free Options Greeks Calculators: A Field Spec Sheet
Black-Scholes toys, chain overlays, and what a surplus desk actually needs before trusting a Greek number.
2026-09-29
How to Compare Free Market Data APIs
A checklist for rate limits, freshness, coverage, and licensing before choosing a data source.
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An Open-Source Backtesting Stack for $0
Data, indicators, a vectorized engine, and walk-forward discipline — the surplus parts list for testing ideas without a Bloomberg.
2026-09-22
Build a Screener With $0 of Tooling
Free data + open-source charting + a spreadsheet brain. Full parts manifest inside.