Jane Street has been barred from the Indian securities market by its markets regulator, which has said the U.S. firm used its trading strategies to "manipulate" a key stock market index, leading to losses for millions of retail investors,

A temporary trading ban imposed by India’s securities regulator on Jane Street Group LLC is fueling concerns that volumes in the nation’s bustling derivatives market may drop, hurting business at the top exchange.

As quant trading firm Jane Street faces regulatory heat in India, corporate filings show that its two local units—JSI Investments and JSI2 Investments—appear to be thinly staffed and are effectively controlled by foreign executives.