What Sebi’s 15% ‘hard ceiling’ on open interest means for broker growth, customers: Zerodha’s Nithin Kamath explains by ET Markets | January 6, 2026 8:05 pm | Indian Stocks, Market, News Zerodha founder Nithin Kamath said SEBI’s 15% open interest cap restricts broker growth but protects consumers by limiting concentration risk, ensuring no single broker dominates markets while encouraging overall industry expansion.