Compare · Differences, not disparagement
Composer (by SoFi) vs Chat·Backtest
Composer is a no-code automated-trading platform where you build rule-based strategies called symphonies, backtest them, and have Composer's own brokerage execute and rebalance them. It joined SoFi in an announcement dated June 23, 2026.
Everything below about Composer (by SoFi) was read from their own site on August 6, 2026, and every row links its source. Pricing and features change — if you find something out of date here, tell us and we’ll fix it.
Feature by feature
| Feature | Composer (by SoFi) | Chat·Backtest |
|---|---|---|
| What it is | A no-code portfolio-automation platform. Their framing: "Build trading algorithms with AI, backtest them, then execute—all in one platform." (source) | An AI strategy lab. Describe a strategy in plain English, get exact inspectable rules, and run them on about two decades of data. We are not a broker and not a charting platform. |
| Building a strategy | A visual no-code editor with blocks like "Apply weighting" and "If this, then that", plus an AI path — "Bring your trading strategies to life by chatting with Composer". No user-facing scripting language is advertised. (source) | Plain English, edited by chat. The rules it generates are readable and exportable — no black box, and no language to learn. The rule grammar is deliberately bounded: anything it cannot express, it cannot run. |
| Backtesting | Included with no subscription. Backtests use "daily adjusted closing prices" that "don't represent real quotes from any point during the trading day", with a default slippage of 1 basis point. (source) | Built in and free to start — the first backtest needs no signup. Daily bars for everyone; intraday timeframes on Pro and above. |
| Markets & data | Stocks and ETFs, from "enterprise-level data sources, including Xignite and Polygon", with "data as far back as 1970 in some cases" and a date picker going back 30 years. Crypto was removed on January 31, 2026. (source) | US stocks and ETFs on daily bars, with intraday on Pro and the full US universe plus crypto on Max. This is the narrowest coverage on this page — every product here beats us on markets and data depth. |
| Forward testing | A "Watch" feature gives a symphony "a simulated $1000 (just like paper trading) to let you monitor the symphony over time". No Composer page we read states whether the rules are locked once watching begins. (source) | Freeze a strategy and deploy it. The spec is hashed at deploy and the store rejects edits to it; a daily worker replays the frozen rules on closed candles and appends the result. |
| Public track record | A Symphony Database is browsable without logging in, marked "Updated Daily", with an OOS Start Date column beside out-of-sample return, Sharpe, max drawdown and Calmar. Individual symphonies are "private by default"; sharing is opt-in by link. (source) | A public, append-only ledger. Backtest and forward curves sit side by side and are never merged, a revised strategy starts a new record at zero, and strategies that lose stay on the board. |
| Live trading | Yes — Composer is itself the broker. Composer Securities LLC is SEC-registered and a FINRA/SIPC member, clearing through Alpaca and Apex. Trades are aggregated into a daily window (3:45–4:00 PM ET) as "not held" orders. (source) | None, by design. No broker connections, no order execution, no signals, no price predictions. The exports exist so you can wire that up elsewhere yourself. |
| Export / portability | Strategy logic is retrievable as EDN through the API, and symphonies can be shared by link or copied between accounts. Transfer and order history export to CSV. (source) | The full spec as JSON plus a runnable Python file, on every plan including free. It is your strategy, not ours to hold. |
| Free tier | Build and backtest is priced "No subscription": AI idea generation, API access, no-code build and backtest, and save/watch/share. Direct Trading is documented as not requiring the Trading Pass. (source) | First backtest with no signup. A free account adds daily-timeframe runs, chat edits, exports and one public deployment — no intraday, no crypto, 10 symbols per run. |
Pricing
| Composer (by SoFi) | Chat·Backtest |
|---|---|
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What Composer (by SoFi) does better
- Composer actually trades. It is a registered broker-dealer that holds the account and rebalances toward your target allocations — a strategy you build there is running with real money by the next trading day. Nothing here does that, on purpose.
- Direct Trading covers individual stocks, ETFs and options, including covered calls and cash-secured puts. We have no options support of any kind.
- Backtesting is free with no subscription and no published run cap.
- The public Symphony Database spans 115+ pages of community strategies with out-of-sample columns, browsable without an account. Our ledger is far smaller.
- Deeper history — their date picker reaches back 30 years, against our roughly two decades.
The part that is actually different
Every product on this page can produce a backtest, and a backtest is worth having — it kills bad ideas cheaply and shows you how a strategy loses. But a backtest is graded on an exam whose answers already existed when the rules were written. With enough attempts, random noise produces a beautiful one.
Here, a strategy can be frozen: the rules are hashed at deploy and the store refuses to edit them afterwards. From that day it is scored on data that did not exist when it was written, and the record is append-only. Strategies that lose stay on the board.
That is the difference — not better indicators, and not more markets, where we lose to everything on this list. It is a record that means something because it could have gone badly in public. It is our own database with a spec hash, not an audit: what we can honestly claim is frozen, public, and append-only.
Which one you actually want
Pick Composer (by SoFi) if: you want the strategy to actually run with your money, in one place, without wiring anything up yourself.
Pick Chat·Backtest if: you want to prove a strategy works on data nobody had when you wrote it, in public, before any money is involved.