Foreign Institutional Investors (FIIs) are investment institutions located outside India that invest in Indian securities. They include foreign mutual funds, hedge funds, pension funds, insurance companies, sovereign wealth funds, and global banks. FIIs bring foreign capital into Indian markets and are often associated with short-term market volatility because their investments move quickly across global markets.
Domestic Institutional Investors (DIIs) are large investment institutions within India, such as Indian mutual funds, insurance companies (LIC being the largest), banks, pension funds, and other domestic financial institutions. DIIs are generally observed to follow a longer-term investment approach and may offset FII flows during periods of market volatility.