您說得很對, 在回測的時候盡量用worst case來做較好, 否則很容易低估影響力
不過, 這裡說的是 [即時] 市價(時時刻刻都在變動)
主要是用在自動動態更新資料的trade book(A single platform uses quantitative data models and analytic-driven selection to route orders to a suite of destinations. Empower traders to optimize execution and drive down implicit costs. Fully-integrated solutions can help cut costs, increase efficiencies and manage risk.)
如上下兩圖:
尤其對想做mispriced交易的人很重要