LedgerX (MIAX Derivatives Exchange)

aid: ledgerx
name: LedgerX (MIAX Derivatives Exchange)
description: LedgerX LLC, doing business as MIAX Derivatives Exchange (MIAXdx), is a CFTC-regulated derivatives venue registered
  as a Designated Contract Market (DCM), Swap Execution Facility (SEF) and Derivatives Clearing Organization (DCO). Founded
  in 2014 under Ledger Holdings Inc. and backed by GV and Lightspeed Venture Partners, it pioneered physically settled, federally
  regulated Bitcoin options and swaps for institutional and retail traders. Ledger Holdings was acquired by West Realm Shires
  (FTX.US) in 2021; after the FTX bankruptcy, Miami International Holdings acquired MIAXdx in May 2023, and in November 2025
  MIAX agreed to sell 90% of the exchange to Robinhood Markets in partnership with Susquehanna International Group. The exchange
  published a public REST API for contracts, positions, trades, balances and order entry, plus a WebSocket market data feed
  carrying action reports, top-of-book updates and exchange heartbeats, authenticated with JWT API keys. Its physically settled
  DCM/SEF products were delisted in July 2024 and the public developer surface (docs, api and trade hosts, status page) is
  currently unreachable or inactive.
url: https://raw.githubusercontent.com/api-evangelist/ledgerx/refs/heads/main/apis.yml
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://app.ledgerx.com/icon-192x192.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- gv
- lightspeed-venture-partners
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Enterprise
- Financial Services
- Derivatives
- Trading
- Cryptocurrency
- Bitcoin
- Exchange
- Market Data
- WebSockets
- Regulated Markets
apis:
- aid: ledgerx:market-data
  name: MIAXdx Market Data and Account API
  description: Public and authenticated REST API on api.ledgerx.com covering exchange contracts, traded contracts, contract
    tickers, positions, trades (own and global), upcoming exchange holidays and account balances. Responses are paginated
    with offset/limit and a meta navigation object, and endpoints are individually rate limited by IP.
  humanURL: https://docs.miaxdx.com/reference/overview
  baseURL: https://api.ledgerx.com
  tags:
  - Market Data
  - Trading
  - Derivatives
  properties:
  - type: APIReference
    url: https://docs.miaxdx.com/reference/overview
  - type: AsyncAPI
    url: asyncapi/ledgerx-market-data-asyncapi.yml
- aid: ledgerx:trading
  name: MIAXdx Trading API
  description: Authenticated order-entry REST API on trade.ledgerx.com for listing resting limit orders, placing orders, cancelling
    a single order or all orders for an MPID, atomically cancel-replacing an order, and retrieving the current book state
    for a contract. Orders are tracked by the message id (mid) returned on submission and followed over the WebSocket feed.
  humanURL: https://docs.miaxdx.com/reference/open-orders
  baseURL: https://trade.ledgerx.com
  tags:
  - Trading
  - Order Entry
  - Derivatives
  properties:
  - type: APIReference
    url: https://docs.miaxdx.com/reference/open-orders
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://app.ledgerx.com
- type: Documentation
  url: https://docs.miaxdx.com
- type: APIReference
  url: https://docs.miaxdx.com/reference/overview
- type: GettingStarted
  url: https://docs.miaxdx.com/docs/api-key
- type: Support
  url: https://support.miaxdx.com/hc/en-us
- type: SignUp
  url: https://app.ledgerx.com
- type: ChangeLog
  url: https://docs.miaxdx.com/changelog
- type: ChangeLog
  url: changelog/ledgerx-changelog.yml
- type: Authentication
  url: authentication/ledgerx-authentication.yml
- type: Conventions
  url: conventions/ledgerx-conventions.yml
- type: ErrorCatalog
  url: errors/ledgerx-error-codes.yml
- type: RateLimits
  url: rate-limits/ledgerx-rate-limits.yml
- type: Lifecycle
  url: lifecycle/ledgerx-lifecycle.yml
- type: Conformance
  url: conformance/ledgerx-conformance.yml
- type: Compliance
  url: conformance/ledgerx-conformance.yml
- type: DataModel
  url: data-model/ledgerx-data-model.yml
- type: AsyncAPI
  url: asyncapi/ledgerx-market-data-asyncapi.yml
- type: Packages
  url: packages/ledgerx-packages.yml
- type: LLMsTxt
  url: llms/ledgerx-llms.txt
- type: DomainSecurity
  url: security/ledgerx-domain-security.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence