Investing / Stock brokerage APIs

Stock Brokerage and Financial Market APIs

A variety of platforms offer developer-first APIs, clearing services, and market data feeds for building investing and trading applications. These services span embedded brokerage platforms, regulatory clearing houses, and global financial data providers.

Brokerage-as-a-Service and Embedded Investing

DriveWealth provides an API-based Brokerage-as-a-Service platform allowing businesses to embed investing into their products [2]. The integration process follows sequential steps: creating a session token, creating a customer, establishing a trading account, creating an order, and retrieving order details [2]. The platform supports fractional shares starting at $1, over 3,000 ETFs, over 6,000 mutual funds, US equities, fixed income, and options [2].

Atomic offers an end-to-end platform for fintechs and institutions to deliver investing and savings products using developer-first APIs, pre-built experiences, and back-office solutions [5]. Atomic provides wealth management capabilities like custom indexing and bond laddering, cash management accounts with high-yield instruments, and brokerage access to fractional stocks, bonds, mutual funds, ETFs, and alternative investments across U.S. and international markets [5]. Atomic operates as an SEC-licensed investment advisor and FINRA-registered broker-dealer, utilizing custody at BNY Pershing and Bank of New York Mellon [5].

Alpaca is a developer-first API platform for stocks and crypto that features tokenized equities with an Instant Tokenization Network offering instant in-kind mint and redemption with 24/7 API access [3]. Alpaca enables zero-commission trading, backtesting, and execution of multi-leg options strategies, along with cash management programs [3]. The platform provides SDKs in Python, .NET/C#, Go, and Node, and includes security standards such as ISO 27001:2022 and SOC 2 Type II controls [3]. Alpaca offers up to $2.5M in FDIC sweep coverage and SIPC protection up to $500,000 [3].

Clearing, Custody, and Compliance

Apex Clearing Corporation is an SEC-registered broker-dealer and member of FINRA and SIPC [1]. Apex Clearing also serves as a CFTC-registered Futures Commission Merchant and NFA member for commodity futures and options on futures, while cryptocurrency services are offered by Apex Digital Markets LLC [1]. All investments carry risks and returns will fluctuate [1]. Embed is another modern clearing and custody service provider [4].

Market Data APIs and Infrastructure

Polygon.io is a stock market API platform delivering data via flat files, RESTful and WebSocket APIs, and SQL queries in standardized JSON and CSV formats alongside client libraries and tutorials [6]. Real-time data on Polygon.io is delivered at <20ms latency [6].

Twelve Data provides market data APIs, WebSockets, and SDKs covering stocks, forex, crypto, and ETFs across more than 250 exchanges and around 100,000 symbols (or 82,000+ different financial assets spanning over 90+ countries) [7]. Twelve Data achieves an average real-time WebSocket streaming latency of approximately ~170 ms and guarantees a 99.95% SLA, handling over 700M+ API requests daily with peaks over 1M+ per minute [7].

What is not covered

Specific pricing tiers, exact subscription fees, and rate limits for individual API endpoints are not provided across the sources. Detailed technical documentation for implementing specific language SDKs beyond basic platform mentions is omitted.