cTrader — Free C# Backtesting with Modern UI

cTrader is a multi-asset trading platform developed by Spotware, known for its clean modern interface, transparent pricing, and Level II market depth. cTrader Automate (formerly cAlgo) is its algorithmic trading and backtesting environment, using full C# with .NET. The entire platform — including backtesting — is completely free through partner brokers.

cTrader Automate: C# Scripting

cTrader Automate uses standard C# compiled with .NET. Automated strategies are called “cBots” and custom indicators inherit from API base classes. The same cBot code runs in both live trading and backtesting with no changes.

Key characteristics:

Full C# language, compiled with .NET runtime
Built-in code editor with IntelliSense
Visual Studio compatible for advanced development
Event-driven: OnBar(), OnTick(), OnStart(), OnStop()
Robot (cBot) and Indicator base classes
Multi-symbol access via MarketData API
Async/await support for non-blocking operations
NuGet package support — import any .NET library
Account info, positions, pending orders, and market data all accessible

Example — simple cBot:

[Robot(AccessRights = AccessRights.None)]
public class SampleBot : Robot
{
    protected override void OnBar()
    {
        var fast = Indicators.SimpleMovingAverage(Bars.ClosePrices, 10);
        var slow = Indicators.SimpleMovingAverage(Bars.ClosePrices, 50);

        if (fast.Result.Last(1) > slow.Result.Last(1)
            && fast.Result.Last(2) <= slow.Result.Last(2))
            ExecuteMarketOrder(TradeType.Buy, SymbolName, 10000);
    }
}

Difficulty: Intermediate — same as NinjaTrader (both C#), but cTrader’s API is generally considered cleaner and more intuitive. Easier for developers familiar with C#.

Strategy Tester Features

The backtesting engine is built into cTrader Automate. Select a cBot, configure parameters, pick a time range, and run.

Testing Modes

Tick data from server — real tick data where the broker provides it. Highest accuracy.
M1 bar data with tick generation — generates ticks from 1-minute OHLC bars. Lower accuracy, faster execution.
Open prices — bar open only. Fastest, least accurate.

Data quality depends heavily on your broker. Some cTrader brokers provide real recorded tick data; others only have M1 bars. Check with your broker before relying on tick-level results.

Optimization

Grid (exhaustive) search — test every combination of specified parameter ranges
Genetic algorithm — intelligent search for large parameter spaces
Multi-parameter support

Optimization is functional but more basic than NinjaTrader’s. There’s no built-in walk-forward optimization or Monte Carlo simulation.

Results Dashboard

Equity curve and balance curve
Net profit, Sharpe ratio, Sortino ratio, max drawdown, profit factor
Total trades, win rate, average trade
Trade-by-trade list with entry/exit details
Visual backtesting — watch trades execute on chart in real-time

Commission and Swap Modeling

Configurable per-test. By default, inherits commission and swap rates from your broker’s symbol specifications, which is convenient for realistic modeling.

Multi-Timeframe Access

cBots can access data from multiple timeframes within a single backtest. You can reference higher-timeframe bars for signal generation while executing on lower timeframes.

Supported Instruments

Forex — primary focus, all major/minor/exotic pairs
CFDs — indices, commodities, metals, energies
Stocks — via CFDs, broker-dependent
Crypto — growing support, broker-dependent
ETFs — limited, broker-dependent

cTrader is strongest in forex and CFDs. Instrument availability depends entirely on your broker.

Pricing

cTrader is completely free. No platform fees, no license fees, no backtesting fees. Ever.

What	Cost
cTrader Desktop	Free
cTrader Web	Free
cTrader Automate (backtesting)	Free
cTrader Mobile	Free
Demo accounts	Free, unlimited
cTrader Open API	Free
Historical data	Free (provided by broker)

Revenue comes from broker licensing fees — traders pay nothing to Spotware. Your only costs are broker spreads and commissions.

cTrader vs MetaTrader vs NinjaTrader

Feature	cTrader	MT5	NinjaTrader
Language	C# (.NET)	MQL5 (C++-like)	C# (.NET)
Price	Free	Free	Free (backtesting)
UI	Modern, best-looking	Functional	Dated
Tick data	Real (broker-dependent)	Real (broker-dependent)	Tick Replay
Walk-forward	No	Basic forward testing	Yes (full WFA)
Monte Carlo	No	No	Yes
NuGet/.NET access	Yes	No (MQL5 only)	Yes
Multi-symbol backtest	Limited	Yes	Yes (basket)
Primary market	Forex/CFDs	Forex/multi-asset	Futures
Broker availability	Limited	1,000+ brokers	NinjaTrader + IB

Pros

Completely free — no fees for anything
Clean, modern UI — best-looking retail trading platform
Full C# with NuGet support — highly extensible
Level II pricing / depth of market as standard
Real tick data backtesting (where broker supports it)
Same cBot code for backtesting and live trading
Web version available (no install needed)
cTrader Open API for building external tools
Active development by Spotware

Cons

Fewer brokers than MetaTrader — limited availability
Smaller community and ecosystem
No walk-forward optimization
No Monte Carlo simulation
Limited historical data depth (broker-dependent)
No true multi-symbol backtesting in a single test run
Fewer third-party add-ons than MT4/MT5
Desktop app Windows-only (web version is cross-platform)
Documentation not as extensive as MQL5 or NinjaTrader

Who Is This For?

cTrader is ideal for forex/CFD traders who want a free, modern platform with C# scripting. If you already know C# and trade forex, cTrader Automate is arguably the cleanest API available. The main trade-off vs NinjaTrader: no walk-forward or Monte Carlo. The trade-off vs MetaTrader: fewer brokers and smaller community.