The LSE Directory / Data providers
Marketstack is a REST API product that delivers stock market data in JSON format: real-time and intraday quotes, end-of-day historical prices, and reference data on tickers, exchanges, currencies and timezones. Data is pulled programmatically over HTTPS, so the product is built for developers embedding price feeds into trading platforms, portfolio trackers, research tools and back-office systems rather than for a terminal-style end user interface. In 2026 the company added a set of EDGAR endpoints (CIK lookup by company name and vice versa, company submissions, company facts, and US GAAP accounting concepts) that pull structured filing and financial statement data directly from SEC databases, extending the product from price data into filings and compliance use cases. Within the market data API category, Marketstack's positioning is low cost and self serve rather than institutional grade: it competes with other developer first data APIs on price and ease of integration, not on exchange direct colocation feeds or tick level depth. Its free tier (100 requests per month, end of day data only) and entry paid tier (10,000 requests per month, from 9.99 USD monthly) target individual developers, students and small teams; usage metered paid tiers scale up to a 500,000 request business plan plus custom enterprise pricing for higher volume. The company's own marketing describes it as a cost effective alternative to scraping free sources such as Yahoo Finance, which points at hobbyist and small application builders as much as financial institutions. Marketstack is a product of apilayer, a Vienna based cloud API company founded by brothers Julian and Paul Zehetmayr (Paul Zehetmayr is CEO and co-founder) whose portfolio also includes currencylayer, fixer, ipstack, weatherstack and aviationstack. Marketstack itself launched in early 2018 under a different name, positioned as a cheaper alternative to scraped free data. Idera, Inc., a Houston based portfolio company owned by the private equity firms HGGC, Partners Group and TA Associates, acquired apilayer Data Products GmbH on January 18, 2021 (announced via Idera's own press release and confirmed by Businesswire and Crunchbase); apilayer's press release at the time of that deal stated its products served more than 500,000 customers including Amazon, Apple, Slack, Airbnb, Uber, Facebook and Zendesk, though that figure describes apilayer's full API portfolio rather than Marketstack alone. Marketstack's own site states coverage of 170,000-plus stock tickers across 70-plus global exchanges and more than 30 years of historical data; note the company's various pages give inconsistent ticker counts (a pricing page states 30,000-plus, an older archived GitHub README states 125,000-plus), so the exact figure should be treated as approximate marketing copy rather than an audited number. As of mid-2026 the company's most recent visible product move is the EDGAR filings expansion described above, positioning Marketstack to compete for financial-research and compliance-tooling use cases that were previously outside a pure price-data API.
