Participatory notes (P-Notes) allow foreign investors to invest in Indian stock markets without directly registering with the market regulator SEBI. The Supreme Court has asked SEBI to issue guidelines to curb the flow of black money through P-Notes by better identifying their real owners. In response, the Indian stock market fell over 500 points on concerns that restrictions on P-Notes could reduce foreign investment inflows. SEBI has taken measures like increased reporting requirements and restrictions on certain types of P-Notes to balance curbing black money while not unduly impacting foreign investment.