TL;DR
TradingView strategy tests are useful for signal validation but actively misleading for prop-firm planning. Six concrete misses: spread, slippage, commission per lot, weekend gap, news lockout, and firm-rule enforcement. Always re-run on a firm-rule-aware backtester before paying for an eval.
TradingView's Pine Script strategy tester is the most-used backtest tool in retail trading. It is also the most-misread. Every week we see operators post equity curves on Discord, "+18% annualised, 67% win-rate", and book the FTMO challenge the same day. Two weeks later the same operator posts "I don't understand, my strategy just busted FTMO on day 4." The strategy didn't bust. The backtest never reflected what a real eval would do.
What TradingView leaves out
Six omissions matter. Each one individually is fixable; combined, they invalidate any backtest you plan to act on at a prop firm.
- Spread. Default Pine Script assumes mid-price entry + exit. Real brokers quote bid/ask, and the spread on EURUSD widens from 0.2 pips during London to 2–4 pips at the New York rollover and 10+ pips at NFP release.
- Slippage. Pine's "slippage" parameter is a static tick count. Real slippage scales with order size, instrument liquidity, and time-of-day. A 1-pip slippage assumption on a scalping strategy understates real costs by 60–80% on most prop-firm brokers.
- Commission. The default is zero. Real prop-firm broker commission ranges from $3 to $7 per lot round-trip; a strategy that does 200 trades a month pays $600–$1,400 in commission alone.
- Weekend gap. Pine treats Friday close → Monday open as continuous bars. Real markets gap. A strategy holding USDJPY over an unexpected weekend BOJ statement can wake up to a 50-pip gap that breaches the firm's daily-loss cap before any chart updates.
- News lockout. Pine has no concept of "no positions during high-impact news." A backtest that includes 4 NFP entries (each one a perfect breakout) is invalid at every prop firm except FTMO.
- Firm rules. Most importantly, Pine has zero concept of the daily-loss cap, trailing drawdown, consistency rule, or minimum profitable days. A strategy that nets +20% on the year may have busted the daily cap on three separate days en route.
The asymmetric impact: it's not noise, it's bias
Every one of those omissions biases TradingView results in the same direction, making the strategy look better than it is. Spread costs are subtracted from your edge, not added. Slippage hurts entries and exits the same way. Commission is a pure subtraction. Weekend gaps and news events are tail risk that disproportionately produces losses, not wins. Firm-rule enforcement only converts profitable runs into busted accounts, never the reverse. The error doesn't average out over a long backtest; it compounds.
How to re-test before the eval fee
The minimum bar for a backtest you can act on at a prop firm: spread modelled at 1.5× the broker's typical, slippage modelled at 1.5–2 pips per trade, commission modelled at $5 per lot, news entries excluded (or capped at a single non-dominant source), weekend holds either banned or flagged, and firm rules enforced tick-by-tick. The Glitch Executor backtester applies all six by default, and emits a verdict-card showing the per-firm pass/fail. Run it before the eval, not after.
| Omission | TradingView default | Realistic value | Edge impact |
|---|---|---|---|
| Spread | 0 pips | 1.5× broker typical | −10% to −25% on scalping strategies |
| Slippage | 0–1 pips | 1.5–2 pips per trade | −5% to −15% |
| Commission | $0 | $3–$7 per lot round-trip | −$3–$7 per closed trade |
| Weekend gap | continuous | ~50% probability of >20 pip gap | tail risk, irregular |
| News lockout | ignored | enforced ±2 min | removes 5–15% of profitable trades |
| Firm rules | none | tick-by-tick enforcement | binary, pass or breach |
The actual workflow
- Develop the strategy on TradingView. Get to a stable signal you trust.
- Export the strategy parameters to Strategy IR (or re-encode in Glitch Executor's quick-rule, visual builder, or code editor).
- Run the firm-rule-aware backtest against the firm you plan to eval at, with realistic spread + slippage + commission applied.
- If the verdict is PASS, run the same test against an adverse market regime (different year, different volatility profile) for robustness.
- Only then book the eval.
Citations
FAQ
- Can I just turn on spread + slippage in TradingView and call it good?
- Better than nothing, but still misses commission, weekend gaps, news lockout, and firm-rule enforcement. The spread + slippage knobs are static, they don't scale with time-of-day or volatility regime. Useful for sanity-checking; not decision-grade for an eval.
- Does Pine Script v5 fix any of these?
- No. v5 added bracket orders and richer plotting; the strategy tester's underlying model is unchanged. Spread, slippage, and commission are still flat parameters. Firm rules are still absent.
- Is MetaTrader Strategy Tester better?
- Marginally, MT5 Strategy Tester models real broker-tick data on the "Every tick" mode, which captures spread + slippage more honestly. But it still has no concept of firm rules. You can pass MT5 ST and bust FTMO.
- How much does each omission cost a typical strategy?
- Order of magnitude: spread + commission combined eat 10–25% of gross edge on a typical scalping system. Weekend + news omissions are tail-risk that produces irregular breach events, not a steady percentage. Firm rules are binary, they don't cost a percentage, they decide pass/fail.
- Where can I read the firm rule each backtest enforces?
- On the per-firm pages at /prop-firms/{firm} on this site, or directly in the firm-rule audit changelog. Each rule is sourced to the firm's own terms page.
- Can I run firm-rule backtests for free on Glitch Executor?
- Yes, the free tier includes one backtest per day with firm-rule verdict against any one supported firm. Pro tier unlocks unlimited backtests + all six firms in one sweep.
How we maintain accuracy
Reviewed by Ryan Tran, Strategy Lead, Glitch Executor. Every quantitative claim cites a primary source; firm-rule values come from the firm-rule registry audited quarterly in this repo. No paid placements, no fabricated reviews.
Post last reviewed . Tier 1 surface last reviewed .
Written by Ryan Tran
Strategy Lead · Glitch ExecutorWrites on prop-firm rule modelling, backtest correctness, and why most "passed challenge" stories don't reproduce.
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