There is a difference between a backtest that tells you a strategy works and one that tells you it will survive a live $USDTRY or $USDZAR tr

There is a difference between a backtest that tells you a strategy works and one that tells you it will survive a live $USDTRY or $USDZAR trading session. Most retail backtests on exotic pairs fail the first test of seriousness: they use point-data from a single feed without accounting for spreads, execution latency, or the thin-liquidity regime that exists outside peak trading windows. The result is a curve that looks exceptional in a Python notebook and produces a margin call on the second live trade. The Spread Problem Is Structural On major currency pairs, a 0.5–1 pip spread is baked...