A trading backtester that runs fully inside the browser
TradingSFX, a SaaS, added a feature after users asked for it for about a year. Traders can replay old charts one candle at a time, place simulated trades, and check whether a strategy might work before risking real money. Similar standalone tools usually cost $20 to $40 per month, but this version sits inside the journal so test trades and real trades can be reviewed in the same .
Users import their own from any broker export, and the browser handles parsing, storage, and time-frame . Candle data does not go to the server, which lowers data licensing and server costs while keeping the user’s market data on their own device. The tool stores up to 5 million candles in IndexedDB, keeps only a nearby slice of data in memory during playback, trims old data during , and uses a size-limited cache for converted time frames.
One year of 1-minute data can be scrubbed smoothly on a mid-range laptop. If one candle hits both the stop loss and the take profit, the system counts the stop loss first, which makes the test result more conservative.
Key points
- The most requested feature was old charts before risking real money.
- Standalone tools often cost $20 to $40 per month, so bundling it into a journal gives the SaaS a stronger reason to stay subscribed.
- Users import broker , and the browser processes the data without sending candles to the server.
- IndexedDB stores up to 5 million candles, while memory use is controlled by loading only the active playback area.
- When both stop loss and take profit are touched in one candle, the tool counts the stop loss first.