feat(tick): add tick signal generation and feature extraction functions

Tick signal generation (src/signals/tick_signals.rs):
- tick_momentum_entry: O(N) single-pass entry signal array from spread/BSI/return
  gates with cooldown enforcement; replaces the Python O(N×120) entry-check loop
- tick_momentum_exit: time-based (EOD) exit bool array from tick timestamps

Tick feature extraction (src/indicators/tick_features.rs):
- tick_spread_pct: (ask-bid)/mid * 100, element-wise
- buy_sell_imbalance_delta: per-tick delta BSI from Zerodha cumulative session
  totals — fixes the ~0.95 all-day artefact from raw cumulative sums
- return_window: lookback return over configurable time window, binary search
  O(N log N); returns NaN where history insufficient (no silent pass-through)
- realized_vol_rolling: rolling stddev of log-returns as realized vol proxy
- oi_position_pct: OI position within day's high/low range [0, 100]
- tick_velocity: rolling ticks/min over configurable window

Python bindings: compute_tick_entry_signals, compute_tick_exit_signals,
tick_spread_pct, buy_sell_imbalance_delta, return_window, realized_vol_rolling,
oi_position_pct, tick_velocity — all with numpy array I/O and default args.

15 new Rust unit tests (7 signal, 8 feature); 153 total, 0 failed.

Co-Authored-By: porcelaincode <contact@alphabench.in>

python/raptorbt/__init__.py

@@ -32,6 +32,16 @@ from raptorbt._raptorbt import (
     batch_spread_backtest,
     # Monte Carlo simulation
     simulate_portfolio_mc,
+    # Tick signal functions
+    compute_tick_entry_signals,
+    compute_tick_exit_signals,
+    # Tick feature functions
+    tick_spread_pct,
+    buy_sell_imbalance_delta,
+    return_window,
+    realized_vol_rolling,
+    oi_position_pct,
+    tick_velocity,
     # Indicator functions
     sma,
     ema,
@@ -72,6 +82,16 @@ __all__ = [
     "batch_spread_backtest",
     # Monte Carlo simulation
     "simulate_portfolio_mc",
+    # Tick signal functions
+    "compute_tick_entry_signals",
+    "compute_tick_exit_signals",
+    # Tick feature functions
+    "tick_spread_pct",
+    "buy_sell_imbalance_delta",
+    "return_window",
+    "realized_vol_rolling",
+    "oi_position_pct",
+    "tick_velocity",
     # Indicator functions
     "sma",
     "ema",

src/indicators/mod.rs

@@ -6,6 +6,7 @@
 pub mod momentum;
 pub mod rolling;
 pub mod strength;
+pub mod tick_features;
 pub mod trend;
 pub mod volatility;
 pub mod volume;
@@ -13,6 +14,10 @@ pub mod volume;
 pub use momentum::{macd, rsi, stochastic, MacdResult, StochasticResult};
 pub use rolling::{rolling_max, rolling_min};
 pub use strength::adx;
+pub use tick_features::{
+    buy_sell_imbalance_delta, oi_position_pct, realized_vol_rolling, return_window, spread_pct,
+    tick_velocity,
+};
 pub use trend::{ema, sma, supertrend, SupertrendResult};
 pub use volatility::{atr, bollinger_bands, BollingerBandsResult};
 pub use volume::{obv, vwap};

src/indicators/tick_features.rs

@@ -0,0 +1,246 @@
+//! Tick-level feature extraction functions.
+//!
+//! All functions accept parallel arrays (one element per tick) and return a
+//! Vec<f64> of the same length. NaN is used where the feature is undefined
+//! (e.g. insufficient history for a lookback window).
+//!
+//! These are building blocks for the signal generation layer — compute features
+//! once on the full tick window, then pass the resulting arrays to
+//! `tick_signals::tick_momentum_entry`.
+
+/// Per-tick bid/ask spread as a percentage of the mid price.
+///
+/// Returns 0.0 where both bid and ask are zero.
+pub fn spread_pct(bid: &[f64], ask: &[f64]) -> Vec<f64> {
+    bid.iter()
+        .zip(ask.iter())
+        .map(|(&b, &a)| {
+            let mid = (b + a) / 2.0;
+            if mid > 0.0 {
+                (a - b) / mid * 100.0
+            } else {
+                0.0
+            }
+        })
+        .collect()
+}
+
+/// Per-tick delta BSI from Zerodha cumulative session totals.
+///
+/// Zerodha's `total_buy_qty` / `total_sell_qty` are running sums that grow
+/// monotonically from market open. Computing BSI from raw cumulative values
+/// yields ~0.95 for the whole day (artefact of early-session buy-side dominance).
+///
+/// This function computes the imbalance of the most recent tick's activity only:
+///   `bsi[i] = Δbuy[i] / (Δbuy[i] + Δsell[i])` where `Δbuy[i] = max(0, buy[i] - buy[i-1])`
+///
+/// Returns 0.5 (neutral) where the total delta is zero (no activity).
+pub fn buy_sell_imbalance_delta(
+    buy_qty_cumulative: &[f64],
+    sell_qty_cumulative: &[f64],
+) -> Vec<f64> {
+    let n = buy_qty_cumulative.len();
+    let mut out = vec![0.5_f64; n];
+    for i in 1..n {
+        let db = (buy_qty_cumulative[i] - buy_qty_cumulative[i - 1]).max(0.0);
+        let ds = (sell_qty_cumulative[i] - sell_qty_cumulative[i - 1]).max(0.0);
+        let total = db + ds;
+        if total > 0.0 {
+            out[i] = db / total;
+        }
+    }
+    out
+}
+
+/// Per-tick lookback return over a fixed time window.
+///
+/// For each tick i, finds the latest tick whose timestamp is at most
+/// `timestamps_ns[i] - window_seconds * 1e9` and computes:
+///   `(ltp[i] - ltp_ref) / ltp_ref * 100`
+///
+/// Returns `f64::NAN` for ticks where no reference tick exists (start of series
+/// or insufficient history).
+///
+/// Uses binary search → O(N log N) total.
+pub fn return_window(timestamps_ns: &[i64], ltp: &[f64], window_seconds: f64) -> Vec<f64> {
+    let n = timestamps_ns.len();
+    let window_ns = (window_seconds * 1_000_000_000.0) as i64;
+    let mut out = vec![f64::NAN; n];
+
+    for i in 0..n {
+        let cutoff = timestamps_ns[i] - window_ns;
+        // Binary search for the last index with ts <= cutoff
+        let pos = timestamps_ns[..i].partition_point(|&ts| ts <= cutoff);
+        // pos is the first index > cutoff; we want pos.saturating_sub(1)
+        if pos > 0 {
+            let ref_idx = pos - 1;
+            let ltp_ref = ltp[ref_idx];
+            if ltp_ref > 0.0 {
+                out[i] = (ltp[i] - ltp_ref) / ltp_ref * 100.0;
+            }
+        }
+    }
+    out
+}
+
+/// Rolling realized volatility proxy: annualized stddev of log returns.
+///
+/// For each tick i, computes stddev of log-returns over all ticks within
+/// the preceding `window_seconds`. Returns `f64::NAN` if fewer than 2 ticks
+/// in the window.
+///
+/// O(N²) worst case but typical windows are short (60–300 s at ~80 ticks/min
+/// = 80–400 ticks), making the inner loop fast in practice.
+pub fn realized_vol_rolling(timestamps_ns: &[i64], ltp: &[f64], window_seconds: f64) -> Vec<f64> {
+    let n = timestamps_ns.len();
+    let window_ns = (window_seconds * 1_000_000_000.0) as i64;
+    let mut out = vec![f64::NAN; n];
+
+    for i in 1..n {
+        let cutoff = timestamps_ns[i] - window_ns;
+        // Find the first tick inside the window
+        let start = timestamps_ns[..i].partition_point(|&ts| ts < cutoff);
+        // We need log returns from start..=i
+        let count = i - start;
+        if count < 1 {
+            continue;
+        }
+        let mut log_rets = Vec::with_capacity(count);
+        for j in (start + 1)..=i {
+            if ltp[j - 1] > 0.0 {
+                log_rets.push((ltp[j] / ltp[j - 1]).ln());
+            }
+        }
+        if log_rets.len() < 2 {
+            continue;
+        }
+        let mean = log_rets.iter().sum::<f64>() / log_rets.len() as f64;
+        let variance = log_rets.iter().map(|r| (r - mean).powi(2)).sum::<f64>()
+            / (log_rets.len() - 1) as f64;
+        out[i] = variance.sqrt() * 100.0; // as percentage of price
+    }
+    out
+}
+
+/// Per-tick OI position within the day's high/low range.
+///
+/// Returns `(oi[i] - oi_day_low) / (oi_day_high - oi_day_low) * 100` ∈ [0, 100].
+/// Returns `f64::NAN` where `oi_day_high <= oi_day_low`.
+pub fn oi_position_pct(oi: &[f64], oi_day_high: f64, oi_day_low: f64) -> Vec<f64> {
+    let range = oi_day_high - oi_day_low;
+    if range <= 0.0 {
+        return vec![f64::NAN; oi.len()];
+    }
+    oi.iter()
+        .map(|&o| (o - oi_day_low) / range * 100.0)
+        .collect()
+}
+
+/// Rolling tick velocity: number of ticks per minute in the preceding window.
+///
+/// For each tick i, counts ticks in (timestamps_ns[i] - window_seconds*1e9, timestamps_ns[i]].
+/// Returns 0.0 for the first tick.
+pub fn tick_velocity(timestamps_ns: &[i64], window_seconds: f64) -> Vec<f64> {
+    let n = timestamps_ns.len();
+    let window_ns = (window_seconds * 1_000_000_000.0) as i64;
+    let mut out = vec![0.0_f64; n];
+
+    for i in 1..n {
+        let cutoff = timestamps_ns[i] - window_ns;
+        let start = timestamps_ns[..i].partition_point(|&ts| ts <= cutoff);
+        let count = (i - start + 1) as f64; // include current tick
+        let minutes = window_seconds / 60.0;
+        out[i] = if minutes > 0.0 { count / minutes } else { 0.0 };
+    }
+    out
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_spread_pct_basic() {
+        let bid = vec![100.0, 200.0];
+        let ask = vec![101.0, 202.0];
+        let s = spread_pct(&bid, &ask);
+        // (101-100)/100.5 * 100 ≈ 0.995
+        assert!((s[0] - 0.9950248756218905).abs() < 1e-9);
+        // (202-200)/201 * 100 ≈ 0.995
+        assert!((s[1] - 0.9950248756218905).abs() < 1e-9);
+    }
+
+    #[test]
+    fn test_spread_pct_zero_bid_ask() {
+        let bid = vec![0.0];
+        let ask = vec![0.0];
+        let s = spread_pct(&bid, &ask);
+        assert_eq!(s[0], 0.0);
+    }
+
+    #[test]
+    fn test_bsi_delta_basic() {
+        // Cumulative: buy grows by 100, sell by 0 → bsi = 1.0
+        let buy = vec![1000.0, 1100.0, 1100.0, 1150.0];
+        let sell = vec![800.0, 800.0, 850.0, 850.0];
+        let bsi = buy_sell_imbalance_delta(&buy, &sell);
+        assert_eq!(bsi[0], 0.5); // first tick always neutral
+        assert_eq!(bsi[1], 1.0); // all buy
+        assert_eq!(bsi[2], 0.0); // all sell
+        assert_eq!(bsi[3], 1.0); // all buy
+    }
+
+    #[test]
+    fn test_bsi_delta_no_activity() {
+        // No change → neutral 0.5
+        let buy = vec![1000.0, 1000.0];
+        let sell = vec![800.0, 800.0];
+        let bsi = buy_sell_imbalance_delta(&buy, &sell);
+        assert_eq!(bsi[1], 0.5);
+    }
+
+    #[test]
+    fn test_return_window_basic() {
+        // Ticks at 0s, 30s, 61s, 90s (nanoseconds)
+        let sec = 1_000_000_000_i64;
+        let ts = vec![0, 30 * sec, 61 * sec, 90 * sec];
+        let ltp = vec![100.0, 102.0, 101.0, 105.0];
+        let ret = return_window(&ts, &ltp, 60.0);
+        // ts[0]: no history → NAN
+        assert!(ret[0].is_nan());
+        // ts[1] at 30s: no tick <= -30s → NAN
+        assert!(ret[1].is_nan());
+        // ts[2] at 61s: cutoff = 1s, ts[0]=0 ≤ 1s → ref = ltp[0]=100.0
+        // (101 - 100) / 100 * 100 = 1.0
+        assert!((ret[2] - 1.0).abs() < 1e-9);
+        // ts[3] at 90s: cutoff = 30s, ts[1]=30s ≤ 30s → ref = ltp[1]=102.0
+        // (105 - 102) / 102 * 100 ≈ 2.941
+        assert!((ret[3] - (3.0 / 102.0 * 100.0)).abs() < 1e-9);
+    }
+
+    #[test]
+    fn test_oi_position_pct() {
+        let oi = vec![50.0, 100.0, 150.0];
+        let result = oi_position_pct(&oi, 200.0, 0.0);
+        assert_eq!(result, vec![25.0, 50.0, 75.0]);
+    }
+
+    #[test]
+    fn test_oi_position_pct_no_range() {
+        let oi = vec![100.0, 100.0];
+        let result = oi_position_pct(&oi, 100.0, 100.0);
+        assert!(result[0].is_nan());
+        assert!(result[1].is_nan());
+    }
+
+    #[test]
+    fn test_tick_velocity_basic() {
+        // 4 ticks at 0s, 10s, 20s, 30s; window=60s
+        let sec = 1_000_000_000_i64;
+        let ts = vec![0, 10 * sec, 20 * sec, 30 * sec];
+        let vel = tick_velocity(&ts, 60.0);
+        // At i=3 (30s): ticks in (−30s, 30s] = all 4 → 4 ticks / 1 min = 4.0
+        assert_eq!(vel[0], 0.0);
+        assert!((vel[3] - 4.0).abs() < 1e-9);
+    }
+}

src/lib.rs

@@ -52,6 +52,18 @@ fn _raptorbt(_py: Python<'_>, m: &PyModule) -> PyResult<()> {
     // Register Monte Carlo simulation
     m.add_function(wrap_pyfunction!(python::bindings::simulate_portfolio_mc, m)?)?;
 
+    // Register tick signal functions
+    m.add_function(wrap_pyfunction!(python::bindings::compute_tick_entry_signals, m)?)?;
+    m.add_function(wrap_pyfunction!(python::bindings::compute_tick_exit_signals, m)?)?;
+
+    // Register tick feature functions
+    m.add_function(wrap_pyfunction!(python::bindings::tick_spread_pct, m)?)?;
+    m.add_function(wrap_pyfunction!(python::bindings::buy_sell_imbalance_delta, m)?)?;
+    m.add_function(wrap_pyfunction!(python::bindings::return_window, m)?)?;
+    m.add_function(wrap_pyfunction!(python::bindings::realized_vol_rolling, m)?)?;
+    m.add_function(wrap_pyfunction!(python::bindings::oi_position_pct, m)?)?;
+    m.add_function(wrap_pyfunction!(python::bindings::tick_velocity, m)?)?;
+
     // Register indicator functions
     m.add_function(wrap_pyfunction!(python::bindings::sma, m)?)?;
     m.add_function(wrap_pyfunction!(python::bindings::ema, m)?)?;

src/python/bindings.rs

@@ -1135,6 +1135,192 @@ pub fn run_tick_backtest<'py>(
     Ok(convert_result(result))
 }
 
+// ============================================================================
+// Tick Signal Functions
+// ============================================================================
+
+/// Compute tick momentum entry signals from per-tick feature arrays.
+///
+/// All input arrays must have the same length N. Returns a bool array of length N
+/// where True indicates a valid entry tick (all gates passed, not in cooldown).
+///
+/// Gates (each can be disabled by setting threshold to 0.0):
+///   - spread_pct[i] <= spread_pct_max
+///   - bsi_delta[i] >= bsi_min  (0.0 = disabled)
+///   - |return_1m[i]| >= return_1m_min_abs  (0.0 = disabled; NaN always fails)
+///   - cooldown_ticks between consecutive entries
+///
+/// return_direction: +1 for long (needs positive return_1m), -1 for short.
+#[pyfunction]
+#[pyo3(signature = (
+    spread_pct,
+    bsi_delta,
+    return_1m,
+    spread_pct_max = 5.0,
+    bsi_min = 0.0,
+    return_1m_min_abs = 0.0,
+    return_direction = 1_i8,
+    cooldown_ticks = 10_usize,
+))]
+pub fn compute_tick_entry_signals<'py>(
+    py: Python<'py>,
+    spread_pct: PyReadonlyArray1<f64>,
+    bsi_delta: PyReadonlyArray1<f64>,
+    return_1m: PyReadonlyArray1<f64>,
+    spread_pct_max: f64,
+    bsi_min: f64,
+    return_1m_min_abs: f64,
+    return_direction: i8,
+    cooldown_ticks: usize,
+) -> PyResult<&'py PyArray1<bool>> {
+    let result = crate::signals::tick_signals::tick_momentum_entry(
+        &numpy_to_vec_f64(spread_pct),
+        &numpy_to_vec_f64(bsi_delta),
+        &numpy_to_vec_f64(return_1m),
+        spread_pct_max,
+        bsi_min,
+        return_1m_min_abs,
+        return_direction,
+        cooldown_ticks,
+    );
+    Ok(vec_to_numpy_bool(py, result))
+}
+
+/// Compute time-based exit signals (EOD / session-end).
+///
+/// Sets exit[i] = True for every tick with timestamp >= eod_exit_time_ns.
+/// Set eod_exit_time_ns = 0 to disable (returns all False).
+///
+/// timestamps_ns: nanoseconds-since-epoch for each tick (int64 array).
+#[pyfunction]
+#[pyo3(signature = (timestamps_ns, eod_exit_time_ns = 0_i64))]
+pub fn compute_tick_exit_signals<'py>(
+    py: Python<'py>,
+    timestamps_ns: PyReadonlyArray1<i64>,
+    eod_exit_time_ns: i64,
+) -> PyResult<&'py PyArray1<bool>> {
+    let result = crate::signals::tick_signals::tick_momentum_exit(
+        &numpy_to_vec_i64(timestamps_ns),
+        eod_exit_time_ns,
+    );
+    Ok(vec_to_numpy_bool(py, result))
+}
+
+// ============================================================================
+// Tick Feature Functions
+// ============================================================================
+
+/// Per-tick bid/ask spread as percentage of mid price.
+/// Returns 0.0 where both bid and ask are zero.
+#[pyfunction]
+pub fn tick_spread_pct<'py>(
+    py: Python<'py>,
+    bid: PyReadonlyArray1<f64>,
+    ask: PyReadonlyArray1<f64>,
+) -> PyResult<&'py PyArray1<f64>> {
+    Ok(vec_to_numpy_f64(
+        py,
+        crate::indicators::tick_features::spread_pct(&numpy_to_vec_f64(bid), &numpy_to_vec_f64(ask)),
+    ))
+}
+
+/// Per-tick delta BSI from Zerodha cumulative session totals.
+///
+/// buy_qty_cumulative / sell_qty_cumulative must be the raw cumulative running sums
+/// from Zerodha (NOT already-converted deltas). Returns [0, 1] per tick; 0.5 = neutral.
+#[pyfunction]
+pub fn buy_sell_imbalance_delta<'py>(
+    py: Python<'py>,
+    buy_qty_cumulative: PyReadonlyArray1<f64>,
+    sell_qty_cumulative: PyReadonlyArray1<f64>,
+) -> PyResult<&'py PyArray1<f64>> {
+    Ok(vec_to_numpy_f64(
+        py,
+        crate::indicators::tick_features::buy_sell_imbalance_delta(
+            &numpy_to_vec_f64(buy_qty_cumulative),
+            &numpy_to_vec_f64(sell_qty_cumulative),
+        ),
+    ))
+}
+
+/// Per-tick lookback return over a time window.
+///
+/// timestamps_ns: nanoseconds-since-epoch for each tick.
+/// Returns NaN for ticks without sufficient history.
+#[pyfunction]
+#[pyo3(signature = (timestamps_ns, ltp, window_seconds = 60.0))]
+pub fn return_window<'py>(
+    py: Python<'py>,
+    timestamps_ns: PyReadonlyArray1<i64>,
+    ltp: PyReadonlyArray1<f64>,
+    window_seconds: f64,
+) -> PyResult<&'py PyArray1<f64>> {
+    Ok(vec_to_numpy_f64(
+        py,
+        crate::indicators::tick_features::return_window(
+            &numpy_to_vec_i64(timestamps_ns),
+            &numpy_to_vec_f64(ltp),
+            window_seconds,
+        ),
+    ))
+}
+
+/// Rolling realized volatility proxy: stddev of log-returns over a time window (as %).
+/// Returns NaN for ticks without at least 2 data points in the window.
+#[pyfunction]
+#[pyo3(signature = (timestamps_ns, ltp, window_seconds = 300.0))]
+pub fn realized_vol_rolling<'py>(
+    py: Python<'py>,
+    timestamps_ns: PyReadonlyArray1<i64>,
+    ltp: PyReadonlyArray1<f64>,
+    window_seconds: f64,
+) -> PyResult<&'py PyArray1<f64>> {
+    Ok(vec_to_numpy_f64(
+        py,
+        crate::indicators::tick_features::realized_vol_rolling(
+            &numpy_to_vec_i64(timestamps_ns),
+            &numpy_to_vec_f64(ltp),
+            window_seconds,
+        ),
+    ))
+}
+
+/// Per-tick OI position within the day's high/low range: [0, 100].
+/// Returns NaN where oi_day_high <= oi_day_low.
+#[pyfunction]
+pub fn oi_position_pct<'py>(
+    py: Python<'py>,
+    oi: PyReadonlyArray1<f64>,
+    oi_day_high: f64,
+    oi_day_low: f64,
+) -> PyResult<&'py PyArray1<f64>> {
+    Ok(vec_to_numpy_f64(
+        py,
+        crate::indicators::tick_features::oi_position_pct(
+            &numpy_to_vec_f64(oi),
+            oi_day_high,
+            oi_day_low,
+        ),
+    ))
+}
+
+/// Rolling tick velocity: ticks per minute over the preceding window_seconds.
+#[pyfunction]
+#[pyo3(signature = (timestamps_ns, window_seconds = 60.0))]
+pub fn tick_velocity<'py>(
+    py: Python<'py>,
+    timestamps_ns: PyReadonlyArray1<i64>,
+    window_seconds: f64,
+) -> PyResult<&'py PyArray1<f64>> {
+    Ok(vec_to_numpy_f64(
+        py,
+        crate::indicators::tick_features::tick_velocity(
+            &numpy_to_vec_i64(timestamps_ns),
+            window_seconds,
+        ),
+    ))
+}
+
 // ============================================================================
 // Indicator Functions
 // ============================================================================

src/signals/mod.rs

@@ -5,6 +5,8 @@
 pub mod expression;
 pub mod processor;
 pub mod synchronizer;
+pub mod tick_signals;
 
 pub use processor::SignalProcessor;
 pub use synchronizer::{SignalSynchronizer, SyncMode};
+pub use tick_signals::{tick_momentum_entry, tick_momentum_exit};

src/signals/tick_signals.rs

@@ -0,0 +1,174 @@
+//! Tick-level signal generation for momentum entry/exit.
+//!
+//! Converts precomputed feature arrays (one scalar per tick) into entry and
+//! exit boolean arrays that can be fed directly into `run_tick_backtest`.
+//!
+//! All functions are O(N) single-pass — no backward linear search, no nested
+//! loops. The return_1m feature array must be precomputed by the caller
+//! (via `tick_features::return_window` or equivalent).
+
+/// Generate momentum entry signals from per-tick feature arrays.
+///
+/// All input slices must have the same length N.
+///
+/// Rules applied in order (a failing rule sets entry[i] = false):
+///   1. spread gate: `spread_pct[i] <= spread_pct_max`
+///   2. BSI gate: if `bsi_min > 0.0`, `bsi_delta[i] >= bsi_min`
+///   3. return gate: if `return_1m_min_abs > 0.0`, direction-aligned
+///      `return_1m[i]` must have `abs >= return_1m_min_abs` and correct sign.
+///      NaN return_1m always fails the gate.
+///   4. cooldown: after each entry, suppress the next `cooldown_ticks` ticks.
+///
+/// `return_direction`: +1 for long (return_1m must be positive), -1 for short
+/// (return_1m must be negative).
+pub fn tick_momentum_entry(
+    spread_pct: &[f64],
+    bsi_delta: &[f64],
+    return_1m: &[f64],
+    spread_pct_max: f64,
+    bsi_min: f64,
+    return_1m_min_abs: f64,
+    return_direction: i8,
+    cooldown_ticks: usize,
+) -> Vec<bool> {
+    let n = spread_pct.len();
+    let mut entries = vec![false; n];
+    let mut cooldown_until: usize = 0;
+
+    for i in 0..n {
+        if i < cooldown_until {
+            continue;
+        }
+
+        // Spread gate
+        if spread_pct[i] > spread_pct_max {
+            continue;
+        }
+
+        // BSI delta gate (disabled when bsi_min == 0.0)
+        if bsi_min > 0.0 {
+            let b = if i < bsi_delta.len() { bsi_delta[i] } else { continue };
+            if b < bsi_min {
+                continue;
+            }
+        }
+
+        // 1-minute return gate (disabled when return_1m_min_abs == 0.0)
+        if return_1m_min_abs > 0.0 {
+            let r = if i < return_1m.len() { return_1m[i] } else { continue };
+            if r.is_nan() {
+                continue;
+            }
+            let abs_r = r.abs();
+            if abs_r < return_1m_min_abs {
+                continue;
+            }
+            // Direction alignment: long needs positive return, short needs negative
+            if return_direction > 0 && r < 0.0 {
+                continue;
+            }
+            if return_direction < 0 && r > 0.0 {
+                continue;
+            }
+        }
+
+        entries[i] = true;
+        cooldown_until = i + 1 + cooldown_ticks;
+    }
+
+    entries
+}
+
+/// Generate time-based exit signals (EOD / session-end).
+///
+/// Sets exit[i] = true for every tick at or after `eod_exit_time_ns`.
+/// When `eod_exit_time_ns == 0` all exits are false (disabled).
+///
+/// `timestamps_ns`: nanoseconds-since-epoch timestamp for each tick.
+pub fn tick_momentum_exit(timestamps_ns: &[i64], eod_exit_time_ns: i64) -> Vec<bool> {
+    let n = timestamps_ns.len();
+    if eod_exit_time_ns == 0 {
+        return vec![false; n];
+    }
+    timestamps_ns
+        .iter()
+        .map(|&ts| ts >= eod_exit_time_ns)
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn make_return_1m(vals: &[f64]) -> Vec<f64> {
+        vals.to_vec()
+    }
+
+    #[test]
+    fn test_entry_spread_gate() {
+        // All spreads above max → no entries
+        let spread = vec![3.0, 4.0, 6.0];
+        let bsi = vec![0.6, 0.7, 0.8];
+        let ret = vec![1.0, 1.0, 1.0];
+        let entries = tick_momentum_entry(&spread, &bsi, &ret, 2.0, 0.0, 0.0, 1, 0);
+        assert_eq!(entries, vec![false, false, false]);
+    }
+
+    #[test]
+    fn test_entry_bsi_gate() {
+        let spread = vec![1.0, 1.0, 1.0];
+        let bsi = vec![0.3, 0.6, 0.4]; // only index 1 passes bsi_min=0.5
+        let ret = vec![0.5, 0.5, 0.5];
+        let entries = tick_momentum_entry(&spread, &bsi, &ret, 5.0, 0.5, 0.0, 1, 0);
+        assert_eq!(entries, vec![false, true, false]);
+    }
+
+    #[test]
+    fn test_entry_return_gate_long() {
+        let spread = vec![1.0, 1.0, 1.0, 1.0];
+        let bsi = vec![0.6, 0.6, 0.6, 0.6];
+        // positive, positive, too small, negative
+        let ret = vec![0.5, 1.0, 0.1, -0.5];
+        let entries = tick_momentum_entry(&spread, &bsi, &ret, 5.0, 0.0, 0.3, 1, 0);
+        assert_eq!(entries, vec![true, true, false, false]);
+    }
+
+    #[test]
+    fn test_entry_return_gate_short() {
+        let spread = vec![1.0, 1.0, 1.0];
+        let bsi = vec![0.6, 0.6, 0.6];
+        // negative enough, positive (fails direction), nan
+        let ret = vec![-0.5, 0.5, f64::NAN];
+        let entries = tick_momentum_entry(&spread, &bsi, &ret, 5.0, 0.0, 0.3, -1, 0);
+        assert_eq!(entries, vec![true, false, false]);
+    }
+
+    #[test]
+    fn test_entry_cooldown() {
+        // cooldown_ticks=2: after entry at i=0, next eligible at i=3
+        let spread = vec![1.0; 6];
+        let bsi = vec![0.6; 6];
+        let ret = vec![0.0; 6];
+        let entries = tick_momentum_entry(&spread, &bsi, &ret, 5.0, 0.0, 0.0, 1, 2);
+        assert!(entries[0]);
+        assert!(!entries[1]);
+        assert!(!entries[2]);
+        assert!(entries[3]);
+        assert!(!entries[4]);
+        assert!(!entries[5]);
+    }
+
+    #[test]
+    fn test_exit_disabled() {
+        let ts = vec![1_000_000_i64, 2_000_000, 3_000_000];
+        let exits = tick_momentum_exit(&ts, 0);
+        assert_eq!(exits, vec![false, false, false]);
+    }
+
+    #[test]
+    fn test_exit_eod_fires() {
+        let ts = vec![1_000_i64, 2_000, 3_000, 4_000];
+        let exits = tick_momentum_exit(&ts, 3_000);
+        assert_eq!(exits, vec![false, false, true, true]);
+    }
+}