Why You Should Avoid Using Closed-Source Trading Indicators
A new Pine Script called "[T] Trade Conditions — Indicator by tmp3" just landed on TradingView, and per the listing it's published as closed-source with no stated usage limitations.
Kyle Donnelly, Algorithmic Trader & Market Technician·updated July 29, 2026
That combination — proprietary logic, free access — is the exact setup where most retail traders assume an edge they haven't earned.
What "Closed-Source" Actually Means Here
The script's page states only that the code is hidden and that users can run it freely. There is no published methodology, no parameter table, no out-of-sample performance data attached to the listing, and no stated formula. For a systematic trader, that's three dealbreakers on the first screen. You cannot validate confluence, you cannot stress-test across regimes, and you cannot audit for repainting — three checks I run before any indicator is allowed near live capital.
If the script is computing something as basic as an RSI-EMA composite or a moving-average slope filter, the opacity is harmless. If it's doing regime detection, volatility clustering, or adaptive thresholds, opacity is a structural risk. The listing tells us neither, and that ambiguity is the entire problem.
The Black-Box Trap I See Every Quarter
Every cycle I watch the same pattern repeat: a new closed-source script trends on the platform, traders paste it onto a 5-minute chart, and within a week the comment thread is full of "this changed my trading" testimonials. None of those traders know whether the signal fired on the close of the current bar or repainted from the open. None of them know the lookback. None of them have measured expectancy across a full trend and range regime.
The honest workflow is mechanical, not emotional. Add the indicator to a sandbox chart, export every signal with timestamp and direction, then calculate hit rate, average winner, average loser, profit factor, and max drawdown over a minimum of 200 trades spanning at least one full cycle. If you can't run that audit without seeing the source code, you don't have an edge — you have a bet dressed up as a system.
What I'm Watching
Until tmp3 publishes a description, a parameter list, or a verifiable public track record, this stays in my watchlist folder, not my signal stack. Free usability lowers the cost of evaluation; it does not lower the cost of trusting the output. The script's edge, if it has one, will show up in the numbers — not in the screenshot.