How did D-Mart shares double on day one?

Answer lies in pre-open call auction, which is a 45-minute window for price discovery

Shares of Avenue Supermarts, which operates successful retail chain DMart, doubled during their stock market debut on Tuesday. 

While, DMart is not the first company whose stock has doubled on listing day—there have been at least eight other companies— but it is the first since market regulator Securities and Exchange Board of India (Sebi) introduced listing day circuit filters.  

To curb listing day volatility, Sebi in 2012 introduced circuit filters and the so-called pre-open call auction for IPO stocks.  Depending on the size of the Initial Public Offer (IPO), stocks were allowed to move in a trading band of either 10