Chit funds are a type of savings scheme practiced in India where members contribute periodic installments over a set period, and each member has a chance to receive the total pooled funds determined by auction or lottery. Chit funds are regulated by various state and central acts, which require registration and compliance to prevent misuse. However, some chit funds operate illegally as Ponzi schemes, where operators collect money from new investors to pay existing investors but eventually disappear with the funds. Regulators have formed vigilance cells to detect unauthorized chits and protect investors, especially vulnerable groups, from being defrauded.