Bayesian Trend Posterior [forexobroker]Bayesian Trend Posterior treats each bar as a Bernoulli observation (up vs not-up) and runs a Beta-Bernoulli sequential update over a sliding window. The posterior probability P(next bar up) = (alpha + u) / (alpha + beta + N), where u is the count of up-bars in the window. Schmitt hysteresis on the posterior locks bull or bear regimes, preventing chatter near 0.5.
🔶 ALGORITHM
1. Count up-bars u in the last N closes (close > close ).
2. Posterior mean = (alpha + u) / (alpha + beta + N) using Beta(alpha, beta) prior.
3. Hysteresis: regime locks to +1 when posterior >= upper threshold, locks to -1 when posterior <= lower threshold, holds otherwise.
4. Within a locked regime, an EMA cross provides the entry trigger so the indicator can fire multiple times during sustained trends.
🔶 SIGNAL LOGIC
- Buy: bull regime locked AND close crosses pullback EMA up AND not already long AND cooldown elapsed AND barstate.isconfirmed.
- Sell: bear regime locked AND close crosses pullback EMA down.
- Position-lock state machine.
🔶 INPUTS
- Posterior Window N (default 30)
- Prior alpha (default 2.0)
- Prior beta (default 2.0)
- Upper Hysteresis (default 0.55)
- Lower Hysteresis (default 0.45)
- Pullback EMA Length (default 8)
- Cooldown Bars (default 4)
- Visual: dashboard, glow, EMA toggle, buy / sell colors
🔶 ALERTS
BTP Buy, BTP Sell, BTP Any Signal, BTP Bull Lock, BTP Bear Lock, BTP High Posterior, BTP Low Posterior, BTP Cross 0.5, BTP Webhook JSON.
🔶 LIMITATIONS
- Bernoulli simplification ignores bar size; a tiny up-bar contributes the same as a strong one. Pair with an ATR-aware filter for size-weighted posteriors.
- Window N is the dominant tuning knob: smaller N reacts faster but flips more; larger N is steadier.
- Prior alpha = beta = 2 is uninformative; users with strong directional bias can adjust.
- Hysteresis prevents chatter but slightly delays regime detection vs threshold-only logic.
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