Pine Script v5 vs v6: What Actually Changed for Indicator Devs

v6 isn’t marketed as a major break, but if you maintain ten or twenty production indicators like I do, the cracks show up fast.

First — `request.security()` semantics tightened. Anything you wrote that depended on the old lookahead defaults will quietly produce different bars in v6.

Second — the new array/matrix functions are genuinely useful. I rewrote my multi-symbol scanner template and shaved 40 lines.

Third — strategy.exit comments now persist into the tradelist export consistently. Small thing, but it broke some custom analytics I had pointed at the CSV.

Bottom line: migrate, but migrate carefully. I now run both v5 and v6 in parallel for two weeks before switching live alerts.