BENGALURU, April 29 Reuters Shares of BSE fell as much as 19 on Monday and was set for its worst day ever after India39;s markets regulator asked the exchange operator to pay the regulatory fee on the annual turnover based on the notional value of the options contract.

BSE was the top loser on the Nifty midcap 100 index, which was mostly unchanged.

The exchange operator39;s shares are still up 27.4 this year, including the day39;s fall, outperforming the 9.6 gain in the midcap index.

The Securities and Exchange Board of India SEBI on Friday directed BSE to pay the regulatory fee on the annual turnover based on the notional value of the options contract, along with differential payment for past years with interest.

The company has been calculating annual turnover based on premium value for options contracts.

Derivatives make up for about 40 of BSE39;s financial year 2025 and 2026 profit and higher fees could hit the overall earnings per share by 1518, Jefferies analysts said in a note.

The brokerage lowered its price target on the stock to 2,900 rupees from 3,000 rupees and downgraded the stock to hold from buy.

BSE said the total demand from SEBI stood at 1.65 billion rupees and was evaluating the order.

The shift to notional is a regulatory setback and BSE will have to pay a regulatory fee, which could account for 1326 of adjusted profit after tax for the financial years 202426, HDFC Securities said in a note.

BSE should now hike its options prices to offset the…