Shares of Ujjivan Financial Services Ltd slumped as much as 19% while Equitas Holdings Ltd dropped nearly 28% on Friday after the Reserve Bank of India clarified that promoters of small finance banks must list their banking units separately within three years of operations. The RBI also reiterated that promoters of small finance banks should maintain their stake to at least 40% for a period of five years from the date of commencement of operation of banks. Both the stocks hwiped out nearly entire gains for those who bought shares in initial public offerings. The shares are currently trading below their issue price. Both listed in 2016. Ujjivan Financial touched a record low of Rs 179.60 a share and fell as much as 19.2%, its biggest single-day fall since listing. Equitas Holdings slumped 28% to touch an all-time low of Rs 93.10 a share.