Rebalancer

Rebalancer

Keeps the portfolio at a target weight by computing drift and emitting just-enough trades to close the gap. This is the only strategist in v1 that emits side: sell — it sells the overweight, buys the underweight. See _shared/position-sizing.md §"Target-weight rebalance" for the canonical formula.

Required: _shared/intent-schema.md, _shared/circuit-breakers.md, _shared/position-sizing.md. See references/decision-rules.md for the numeric rules.

Strategy summary

• Target weights: SPY 50%, QQQ 30%, BND 20% (matches dca-investor basket).
• Drift thresholds: Normal 2.5% — fire only on first-of-month. Panic 10% — fire any tick.
• Per-tick clamp: Trade no more than 10% of account value in a single tick (prevents lurching on noisy days).
• Cadence: Monthly (first trading day) for normal drift; off-cadence is allowed only when drift exceeds panic.
• Tax-loss harvesting: Out of scope for v1. A future v2 may check get_equity_positions for unrealized losses on the overweight before selling.

6-phase protocol

Phase 1 — Pre-flight (strategist-side gate)

1. Determine cadence: is today the first trading day of the calendar month? Check via get_equity_quotes last-trade dates to identify the first session of the month.
2. If yes: proceed to phase 2 (normal cadence path).
3. If no: continue to phase 2 anyway, but mark this tick as panic_only — phase 4 will only emit intents if some symbol's drift exceeds panic threshold.

Phase 2 — Compose context

Invoke portfolio-construction with: "Three-line summary of current weight philosophy — equity/bond/cash, tilt, hedges." Then risk-architecture with: "Anything in current positions that suggests trimming faster or slower than normal?"

Both responses go into tick_decision.notes. They do NOT change the numeric rules in v1.

Phase 3 — Signal gather

Parallel calls:

• get_equity_positions(account_number=619508153) — current shares per symbol.
• get_portfolio(account_number=619508153) — total_value for the denominator.
• get_equity_quotes(symbols=allowlist) — current prices to value positions.

Compute current weights:

position_value[symbol] = positions[symbol].quantity * quotes[symbol].last_trade_price
current_weight[symbol] = position_value[symbol] / total_value

Phase 4 — Decide

For each symbol in target_weights:

delta_pct = target_weight - current_weight

if panic_only and abs(delta_pct) < drift_thresholds.panic: skip this symbol
if abs(delta_pct) < drift_thresholds.normal: skip this symbol

delta_usd = delta_pct * total_value
delta_usd = clamp(delta_usd, -total_value * per_tick_clamp_pct, total_value * per_tick_clamp_pct)

intent = {
    "symbol": symbol,
    "side": "buy" if delta_usd > 0 else "sell",
    "quantity_type": "notional",
    "notional_usd": abs(delta_usd),
    "order_type": "market",
    "intent_price": quotes[symbol].last_trade_price,
    "max_slippage_pct": 0.5,
    "time_in_force": "gfd",
    "reason": f"Drift {delta_pct*100:+.1f}% from target {target_weight*100:.0f}%",
    ...
}

Symbols in allowlist but NOT in target_weights are checked: if held, emit a sell intent to liquidate (drift = -current). This handles allowlist contraction.

Phase 5 — Hand off to executor

Standard envelope to _shared/executor. The executor enforces buying-power on the buy side and sellable-shares on the sell side.

Phase 6 — Emit & persist

Write tick_decision. State file at ~/.hermes/profiles/autotrader/state/rebalancer.json records:

{
  "last_normal_cadence_at": "<ISO>",
  "last_panic_fire_at": "<ISO>",
  "rebalance_count": <int>
}

last_normal_cadence_at updates on every normal-cadence run (regardless of whether any intents fired). last_panic_fire_at updates only when a panic intent placed.

Interactive mode

• "Am I drifting?" — run phases 1-4, emit tick_decision with actions: [] if no drift exceeds threshold, otherwise show what would fire. Always review-only.
• "Force rebalance now" — refuse. Cadence is the cadence. Operator can edit frontmatter or wait for next first-of-month.
• "What's my current allocation?" — compute current_weight per symbol and present as a table. Do NOT emit intents.

What this strategist will never do

• Trade tax-inefficiently in v1 (no TLH check — just sells overweight).
• Trade outside the allowlist.
• Buy and sell the same symbol in one tick.
• Run more than once per day in normal-cadence mode.
• Fire on a non-first-of-month unless panic drift is hit.