# Composer No-code rule-based stock and ETF strategies, backtested and then traded for real. *https://stockmarketstack.com/tools/composer · Backtesting Frameworks & Algo Trading Libraries* ## Facts ### At a glance | Field | Value | | --- | --- | | Vendor | Composer | | Category | Backtesting Frameworks & Algo Trading Libraries | | Job | no_code | | Website | https://www.composer.trade | | Pricing model | subscription | | Free tier | true | | Open source | false | | Licence | none | | Self-hosted | false | | Tested hands-on | false | | Last updated | 2026-09-13 | ### Pricing | Tier | USD | Period | | --- | --- | --- | | Build and backtest | 0 USD | month | | Trading Pass | 40 USD | month | | Business Account | on request | month | ### Coverage | Field | Value | | --- | --- | | Asset classes | stocks, etf, options | | Markets | us | | Works outside the US | false | | Data latency | realtime | | Platforms | web, ios | | AI features | assistive | ### Interfaces | Field | Value | | --- | --- | | API | true | | Webhooks | false | | Scripting | none | | Python | false | | Spreadsheet add-in | false | | MCP server | true | | Export | csv | ### Capabilities Yes: backtesting, automation, live_trading, paper_trading, portfolio_tracking, options_analysis No: charting, screening, scanning, broker_import, tax_reporting, alerts, news *Verified: pricing 2026-09-13; capabilities 2026-09-13; coverage 2026-09-13.* ## What it is Composer is a hosted, no-code builder for rule-based equity strategies. You assemble a "symphony" out of blocks — assets, weights, conditionals, filters, groups — backtest it, and hand it to Composer's own brokerage to rebalance on a schedule without you touching it. That last step is the unusual part: most tools in this category stop at a signal, and Composer routes the order itself, through Composer Securities LLC with Alpaca and Apex clearing behind it. SoFi acquired the company in June 2026 and the product carries on unchanged. An AI assistant turns a plain-English description into a symphony you then edit, and Discover surfaces strategies from a library of more than 2,000 that other users built. Both produce an editable rule set rather than a pick, and nothing trades until you invest in it. ## Pricing What the free tier withholds is narrower than it looks: the editor, backtests, watching a strategy forward, the AI and the API are all free, and so is placing your own stock and ETF trades. Only *automated* strategy execution is paid, along with unlimited backtesting and retirement accounts. The Trading Pass costs $40/month month-to-month or $384 a year ($32/month) — and the backtester will model that subscription as a cost if you ask it to, which is fairer than most, though it is off by default. Stock and ETF trades carry no commission, only pass-through SEC and FINRA fees; options are $0.65 per contract plus $5.00 per position exercised or assigned. The deposit minimum is $50 and each symphony needs $50, though Composer recommends $2,500 across the portfolio to avoid unfilled orders, since not every asset is fractionable. ## Data & coverage US stocks, ETFs and listed options. Quotes come from Xignite and Polygon, and the options chain is live. Backtests are a different animal: daily adjusted closing prices, a default slippage assumption of 1 basis point, and a date picker that reaches back 30 years. Crypto is gone — support ended 31 January 2026 and remaining positions were liquidated on 4 February. Crypto ETFs are unaffected. ## Integrations A REST API issues a key and secret and covers accounts, portfolio statistics, symphonies, backtests, direct trading and CSV activity reports. Limits are per key and per endpoint, per minute: most endpoints allow 25 requests a minute, and a handful of symphony and portfolio endpoints are raised to 100, 250 or 500 — the 500 belongs to the per-symphony portfolio statistics call, not to backtesting. There is also a first-party MCP server, so an LLM client can build and backtest symphonies and, with a key, read and trade an account. It is published as the `composer-trade-mcp` package and runs locally against the same REST API; the backtesting tools work without an account at all. It is no longer maintained in the open, though — see Limitations. A help-centre article still says Composer supports no integrations with external apps or platforms, but it was last touched in June 2025, before either the documented API or the MCP server, and it is best read as being about consumer app connections rather than the developer surface. ## Limitations - US residents only, for building and watching as well as trading. - Backtests are daily-close only: no intrabar fills, no simulated limit orders, no intraday strategies at all — the engine rebalances in one scheduled trading period per day. - Symphonies are long-only stocks and ETFs. Options are traded by hand from the chain rather than automated by a strategy, and short selling and margin are not on offer. No futures, no forex, no crypto. - The MCP server is unmaintained and half-abandoned. Its GitHub repository now 404s, the last release was 0.1.7 in July 2025, and the hosted variant the vendor's Claude Desktop extension still points at (`mcp.composer.trade`) no longer resolves. The PyPI package and the REST API behind it do still work, so installing it by name is the only route that does. - Nothing is portable. There is no self-hosted build, and the strategy language is Composer's — a symphony does not leave for another broker. ## Alternatives [QuantConnect](https://stockmarketstack.com/tools/quantconnect) and the Python backtesting libraries if you would rather write code and keep the result portable. [TrendSpider](https://stockmarketstack.com/tools/trendspider) for no-code automation attached to charts rather than a brokerage. [AmiBroker](https://stockmarketstack.com/tools/amibroker) or Wealth-Lab if a desktop licence and your own data suit you better than a subscription that also holds the money. ## FAQ ### Do I need to pay to backtest on Composer? No. Building strategies in the visual editor, backtesting them, watching them forward, sharing them, using the AI assistant, calling the API and placing your own stock and ETF trades are all free. The $40/month Trading Pass is what lets a strategy place trades automatically on your behalf. ### Can I use Composer from outside the US? No. Live trading is US-only, and the vendor's own help centre says you must be in the US even to build and watch strategies. There is no waiting list beyond an email address to ask for early access when it expands. ### Does Composer still support crypto? No. Composer stopped supporting crypto assets and crypto indicators after 31 January 2026 and liquidated the remaining positions and strategies on 4 February 2026. Crypto ETFs such as BITX were unaffected and still trade normally. ### Is Composer still an independent company? No. SoFi acquired it, announced on 23 June 2026. The product still trades under the Composer name — the iOS app is listed as "Composer by SoFi" — and Composer Securities LLC remains the broker-dealer of record. ## Also worth comparing - [Adaptrade Builder](https://stockmarketstack.com/tools/adaptrade-builder.md) — Windows strategy generator — genetic programming writes the rules, you export the code. - [Build Alpha](https://stockmarketstack.com/tools/build-alpha.md) — Point-and-click strategy generation on Windows, exported as code to eight platforms. - [StrategyQuant X](https://stockmarketstack.com/tools/strategyquant-x.md) — Machine-searches for trading strategies, then tries to break them with robustness tests. - [Lumibot](https://stockmarketstack.com/tools/lumibot.md) — One strategy class for backtest and live, plus a built-in LLM agent runtime. - [NautilusTrader](https://stockmarketstack.com/tools/nautilus-trader.md) — Rust core, Python API, one strategy that backtests and trades live unchanged. - [QuantConnect](https://stockmarketstack.com/tools/quantconnect.md) — The open-source LEAN engine, plus a hosted cloud that runs it against real brokers.