SEBI has banned the firm from India’s securities markets. The drama has thrown a bright light on Jane Street, a company of legendary opacity even in an industry that prioritises secrecy. And it could carry political and regulatory consequences, not just for Jane Street, but for an entire, ascendant industry of marketmakers.

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,

It’s not every day that a regulator as methodical and reserved as India’s SEBI accuses one of the world’s largest trading firms of a “sinister scheme.” But that’s what happened last week when Jane Street—one of the “new titans of Wall Street”—was banned from India’s markets over allegations of manipulating prices in one of the fastest-growing derivatives markets on Earth.