Jane Street barred from Indian markets as regulator freezes $566M

According to Indian regulators, every trading day Jane Street would:

1) buy large volumes of stocks and/or stock futures that are part of an index tracking India’s banking sector, early in the day,

2) subsequently place large options trades, betting that the index would decline or volatility would spike later in the day, and

3) later in the day, cash out of the large long positions, dragging the index lower, making far more money on the options trades than on the long positions.

Jane Street can and likely will claim the firm was only arbitraging away pricing inefficiencies, nothing more, nothing less. It was just business as usual, etc., etc.

However, given the scale of the operation, Jane Street's actions sure look like textbook market manipulation. Calling it like I see it.

Ok, but what moron was selling them the puts , and not seeing the pattern after a couple of days of this ? Sebi logic seems questionable.

I assume the moron in question was using Black-Scholes or some similar formula to price those options, and refused to update their prior when they lost money day after day. This happens quite a bit in derivatives markets.

But why would they refuse to? They're there to make money too, after all.