QFII is short for qualified overseas investment institutional funds. Under the QFII system, qualified foreign institutional investors (QFII) will be allowed to remit a certain amount of foreign exchange funds and convert them into local currency, and invest in the local securities market through special accounts under strict supervision and management. All kinds of capital gains, including dividends and bid-ask spreads, can be converted into foreign exchange remittance after examination, which is actually to open the domestic securities market to foreign investors to a limited extent.