Jane Street would very much prefer not to be in the spotlight—especially not the kind that comes with a market regulator’s glare.

The US-based hedge fund places a huge premium on secrecy. So much that many of its senior traders don’t even have Linkedin profiles and its employees are discouraged from wearing company hoodies outside office premises, The Ken has learnt. The firm does not even promote discussion of its trading strategies internally among other teams, an ex-employee said.

But now it’s under the lens. The Securities and Exchange Board of India (Sebi) is reportedlyReutersIndia regulator probes Jane Street's derivative trades over three years, sources say probing Jane Street’s derivatives trades over three years to ascertain if there was a “repeated pattern” of taking outsized positions in index derivativesindex derivativesA derivative that gives the holder the right to buy or sell the value of an underlying index such as the Sensex and the Nifty and moving the index to profit.

In January, The Ken broke the storyThe KenThe mystery fund playing God and wreaking havoc on the stock market about wild moves on weekly expiry daysweekly expiry daysRefers to the expiry date of certain futures and options contracts. Nifty weekly expiries fall on Thursdays. Sensex weekly expiries happen on Tuesdays, leaving India’s options tradersoptions tradersTraders who buy or sell an options contract scrambling and at the mercy of a mystery fund. The latter was playing God, so to speak, and wreaking havoc on the stock market.

If someone can casually move the Nifty by as much as 2% at his discretion, he is nothing short of God in the market.