Why did Manappuram Finance shares fall 17% in one hour?

Manappuram Finance shares fell nearly 17% to ₹147.50 in about an hour after they opened at ₹159.70 on Friday. This comes after RBI ordered the company's subsidiary Asirvad Microfinance to cease and desist sanctions and disbursal of loans due to concerns that the NBFC's pricing policy was in excess or non-compliant. Brokerage firm Jefferies has downgraded Manappuram Finance to 'hold'.