"""波动点数口径 v1：到期指数 − 时段代表指数。"""

from __future__ import annotations

MOVE_POINTS_FORMULA_VERSION = "1.0"


def move_points(settle_index_px: float, index_at_t: float) -> float:
    """signed 点数；绝对值由调用方取 abs。"""
    return float(settle_index_px) - float(index_at_t)