BENGALURU/MUMBAI: New-age stock brokers which are offering trading services at near-zero costs, are changing the old order at a fast pace, on the back of the rapid adoption of technology in India’s banking and financial services space.Bangalore-based tech-driven, low-cost brokerage house Zerodha , started by a former trader nearly eight years ago, has replaced giants like ICICI Securities , HDFC Securities , Kotak Securities , Motilal Oswal and Sharekhan to emerge as the largest broker in India in terms of number of clients, NSE data showed.With 8.47 lakh clients, Zerodha is now ahead of ICICI Securities (8.44 lakh), which was the market leader for nearly a decade. Others lower down the pecking order are HDFC Securities (6.74 lakh), Sharekhan (5.4 lakh), Angel Broking (4.1 lakh) and Kotak Securities (4 lakh).In the last five years Zerodha’s annual growth rate in client addition has been in the range of 200-300%. Some other brokerages having similar models, popularly called discount brokerages, are also growing their cleints at a fast clip. These include Upstox (formerly RKSV), Samco and SAS Online. These brokerages too have seen their client base rise two-three folds in the last two years.Discount brokers are those houses which charge clients significantly lower fees compared to traditional ones, offer only online trading facility but no research support or financial advice. Globally, because of the low cost structure and the trade-and-scoot type of policy, discount brokers are very popular among traders but not so among investors.Zerodha’s rise to the top of the table could be attributed to its first-mover advantage in the space, along with its smart use of technology. For example, at a time when all brokerages were fixed on charging a percentage of the trade value as commission, it introduced a flat fee of Rs 20 per trade.The move, then, was not only brushed aside as a gimmick by large brokerages, some even joked that forget stock trading, for Rs 20 one can’t even buy samosas.According to Nikhil Kamath, co-founder, Zerodha, its growth could also be attributed to transparency and technology prowess. “Our trading platform Kite is one of the most advanced systems in the market. For front-end trading, we provide immense data richness in our charts, graphs and also permit real-time rule based trading. Also we’ve opened our APIs to coders, so they can create their own tools to trade,” Kamath said. “Nearly 90% of our clients use Kite, so its not just about our flat fee structure that is pushing volumes,” he said. Not surprisingly, Zerodha now accounts for more than 10% of all retail trading volumes in the country.To remain ahead of the competition, Zerodha has also invested in unique startups like Smallcase, Streak and Sensibull. On Streak, even non-programmers can develop their trading strategies without learning to code, Sensibull is focused on options trading and strategy while Smallcase helps investors manage low-cost portfolios.