Composer
Composer Technical Briefing
Published April 26, 2022
Supported by Modern Treasury , IowaEDA and Brale
Overview
Ben Rollert, CEO and co-founder of Composer, demos Composer — a trading app that gives retail investors access to systematic investing. Strategies are called "Symphonies" — containers for trading logic and the assets they operate on, much like an ETF is a container for a basket. The demo walks through the strategy library (featured, community, classic), Symphony fact sheets with backtests that actually model slippage and fees (rare in retail products), the visual conditional-logic editor and natural-language descriptions, live editing of conditions and benchmarks, swapping underlying assets, and Composer's fundamental building blocks (weight blocks, assets, filters, conditions) used Lego-style to build recursively nested multi-strategy portfolios like the Dragon Portfolio. Composer supports threshold rebalancing (rebalance only on drift, not calendar) and deploys to real brokerage accounts via Alpaca with fractional market orders.
0:00 Introduction to Composer — systematic investing for retail
Ben Rollert, CEO and co-founder of Composer, introduces Composer — a trading app that gives retail investors access to the power of systematic investing. Rather than picking individual stocks, the product is centered on trading strategies ("Symphonies") and funded like any brokerage account.
0:30 Symphonies — the strategy library
Each tile in Composer's library is a Symphony — a container for trading logic and the assets it operates on, like an ETF is a container for a basket. Featured strategies, community strategies built by influencers, and themed classics are available out of the box.
1:50 Fact sheets, backtests with real slippage and fees
Every Symphony has a fact sheet with a backtest. Composer is one of the few retail products that actually models slippage and transaction fees in backtests — most retail backtests ignore spreads and look unrealistically rosy.
3:00 Visual logic + natural-language descriptions
Symphonies surface as a visual tree of conditional logic plus a natural-language description ("every month ask whether SPY's 60-day cumulative return is above TLT's"), with the currently-active branch highlighted live.
3:30 Symphony editor — edit conditions and rerun backtests
Clicking Edit a Copy opens the Composer Symphony editor. Change the lookback window (60-day to 30-day), swap TLT for QQQ, rerun the backtest on demand, compare historical allocations — all against the original benchmark.
5:00 Compare any Symphony as a benchmark
Any Symphony can be used as a benchmark against any other — so you can stack this strategy against the classic big-tech momentum Symphony and get the Sharpe, max-drawdown, and annualized-return comparison table in place.
6:30 Building blocks — weight blocks, assets, filters, conditions
The fundamental Composer primitives — weight blocks, assets, filter blocks for momentum, conditions for switching. Compose them like Lego to build anything from an equal-weighted SPY+bonds blend to fully nested multi-strategy portfolios.
8:00 The Dragon Portfolio — nested sub-strategies
A real example: the Dragon Portfolio, composed of five nested sub-strategies (long-vol, trended-momentum, fiat alternatives, cyclical growth assets) each made up of further Lego blocks. No other retail product lets you compose this recursively.
9:30 Threshold vs calendar rebalancing
Composer supports threshold rebalancing — rebalance only when allocation drift exceeds a target, instead of on a fixed calendar — which saves meaningfully on trading costs without a research desk.
11:30 Deploy to a real brokerage account via Alpaca
Every Symphony deploys to a funded brokerage account. Composer executes fractional market orders near market close via Alpaca on the backend; the user only sees a single Composer account, and strategies can be shared publicly with a link.
Presented by Ben Rollert — Composer · LinkedIn · website
Topics: Investing & Trading, Capital Markets
