/parabolic-short-trade-planner

Short Risk Management

SEC Rule 201 (Short Sale Restriction)

Triggered when a security's regular-session intraday price drops 10% or more from the prior day's regular-session close. While active:

• New short sales are restricted to prices ABOVE the national best bid (the "uptick rule").
• The restriction holds for the rest of the trading day and the full next trading day.

Implementation note: this skill inherits prior_regular_close from Phase 1's key_levels.prior_close (sourced from FMP's historical-price-eod/full, which is the regular-session 4:00 PM ET close). It does NOT use FMP's quote endpoint previousClose, which can drift to the aftermarket print.

ssr_state_tracker.py persists per-symbol state to state/parabolic_short/ssr_state_<ticker>_<date>.json so today's ssr_triggered_today rolls forward to tomorrow's ssr_carryover_from_prior_day.

Borrow inventory: Alpaca specifics

Alpaca only allows new short opens on Easy-To-Borrow (ETB) names. The adapter encodes this exactly:

can_open_new_short = shortable AND easy_to_borrow
borrow_fee_apr     = 0.0 if easy_to_borrow else None
manual_locate_required = True   # always

A name that is shortable=True but easy_to_borrow=False (HTB) cannot be opened on Alpaca regardless of locate. Phase 2 marks these as borrow_inventory_unavailable (a hard blocker) and renders the plan as plan_status: watch_only.

manual_locate_required is True even on ETB names. The trader still confirms locate at the broker before entry — it's an advisory reason, not blocking, so plans for ETB names stay actionable.

Position sizing

The size_recipe_builder.py outputs:

• risk_usd — per-trade risk in USD (account_size × risk_bps/10000).
• max_position_value_usd — per-symbol position cap (account_size × max_position_pct/100), tightened if current_short_exposure is high.
• shares_formula — string form of the formula. Phase 3 evaluates it at trigger fire when actual entry/stop are known.
• exposure_cap_applied — True if the per-symbol cap was tightened because the aggregate short-book budget was already mostly used.
• remaining_short_exposure_capacity_usd — how much short-book headroom is left.

This deliberately excludes a fixed share count. ORL / first-red / VWAP-fail entries only have known prices intraday, so committing to a share count pre-market would be inaccurate.

Daily loss limits

Not enforced in this MVP. The trader is responsible for honoring account-level circuit breakers. A future revision can add a state/ file recording realized P&L and reject new plans when the daily loss limit is hit.