Deutsche Bank (NYSE:DB) and Credit Suisse (NYSE:CS) will be dropped from the Stoxx 50 index (NYSEARCA:FEU) of European blue-chips starting today due to the so-called "fast-exit" rule.The law states that a component will be deleted if it ranks 75 or below on the respective index's monthly selection lists for a consecutive period of two months.Shares in both companies slumped to record lows post-Brexit and have shed almost 50% of their value year-to-date