Files
qihuo/position_sizing.py
T

98 lines
3.4 KiB
Python

"""期货计仓:固定张数 / 以损定仓(不含币圈全仓杠杆模式)。"""
from __future__ import annotations
import math
from typing import Optional
from contract_specs import get_contract_spec
MODE_FIXED = "fixed"
MODE_RISK = "risk"
# 单笔报单手数上限(防止以损定仓在止损过近时算出超大手数)
DEFAULT_MAX_ORDER_LOTS = 50
def normalize_sizing_mode(raw: str) -> str:
m = (raw or MODE_RISK).strip().lower()
return m if m in (MODE_FIXED, MODE_RISK) else MODE_RISK
def price_precision_from_tick(tick_size: float) -> int:
if tick_size <= 0:
return 0
s = f"{tick_size:.10f}".rstrip("0").rstrip(".")
if "." not in s:
return 0
return len(s.split(".")[1])
def calc_lots_by_risk(
entry: float,
stop_loss: float,
direction: str,
capital: float,
risk_percent: float,
ths_code: str,
*,
max_lots: Optional[int] = None,
) -> tuple[Optional[int], Optional[str]]:
"""以损定仓:返回 (手数, 错误信息)。"""
try:
entry_f = float(entry)
sl_f = float(stop_loss)
cap = float(capital)
rp = float(risk_percent)
except (TypeError, ValueError):
return None, "参数格式错误"
if entry_f <= 0 or cap <= 0 or rp <= 0:
return None, "入场价、资金或风险比例无效"
spec = get_contract_spec(ths_code)
mult = spec["mult"]
d = (direction or "long").strip().lower()
if d == "short":
per_lot_risk = (sl_f - entry_f) * mult
else:
per_lot_risk = (entry_f - sl_f) * mult
if per_lot_risk <= 0:
return None, "止损方向与入场价不匹配"
budget = cap * rp / 100.0
lots = int(math.floor(budget / per_lot_risk))
if lots < 1:
return None, f"{rp}% 风险预算,当前止损距离下不足 1 手"
margin_rate = spec["margin_rate"]
margin_per_lot = entry_f * mult * margin_rate
max_by_margin = int(math.floor(cap * 0.85 / margin_per_lot)) if margin_per_lot > 0 else lots
if max_by_margin < 1:
return None, "可用资金不足以覆盖 1 手保证金"
lots = min(lots, max_by_margin)
cap_lots = max_lots if max_lots is not None else DEFAULT_MAX_ORDER_LOTS
lots = min(lots, cap_lots)
return lots, None
def calc_order_tick_metrics(ths_code: str, lots: float, price: Optional[float] = None) -> dict:
"""下单区展示:最小变动价位、每跳盈亏、保证金等。"""
spec = get_contract_spec(ths_code)
mult = int(spec["mult"])
tick = float(spec.get("tick_size") or 1.0)
margin_rate = float(spec["margin_rate"])
lots_i = max(1, int(lots or 1))
tick_value_per_lot = round(tick * mult, 4)
tick_value_total = round(tick_value_per_lot * lots_i, 2)
prec = price_precision_from_tick(tick)
mark = float(price) if price else 0.0
margin_per_lot = round(mark * mult * margin_rate, 2) if mark > 0 else None
margin_total = round(margin_per_lot * lots_i, 2) if margin_per_lot else None
return {
"mult": mult,
"tick_size": tick,
"price_precision": prec,
"tick_value_per_lot": tick_value_per_lot,
"tick_value_total": tick_value_total,
"lots": lots_i,
"margin_per_lot": margin_per_lot,
"margin_total": margin_total,
"margin_rate": margin_rate,
}