Whether arbitrage or manipulation, the Jane Street episode highlights a critical truth: markets need more transparency, more accountability, and more human judgment.

India has been a money machine for Jane Street, netting the trading giant more than $4bn in profits in just over two years. But it is now the source of a scandal that is imperilling the Wall Street firm’s golden run.

This was originally published in the India File newsletter, which is issued every Tuesday. Sign up here to get the latest news from India and how it matters to the world.