This story is part of Forbes’ coverage of India’s Richest 2022. See the full list here.

The work-from-home trend helped brothers Nithin and Nikhil Kamath super-size their pioneering online discount brokerage Zerodha. The Bangalore-based company has seen its client base grow nearly fivefold to over 10 million in September from the start of the pandemic in 2020.

Zerodha posted solid growth in the year ended March 31. Revenue rose 82% to 49.6 billion rupees ($609 million) while net profit climbed 87% to 21 billion rupees. The brothers, who own the private company, saw their ranking in the list rise to No. 58 with a net worth of $3.45 billion.

The brothers disrupted the brokerage industry with Zerodha, launched in 2010 with the goal of making investing more user-friendly, transparent and cheaper. (Zerodha means zero “rodha,” or barriers, in Sanskrit.) It was among the first of the brokerages to fully disclose all charges, and attracted day traders by keeping charges low—at 20 rupees or 0.03% per trade, whichever was lower.

Competition has intensified with other discount brokerages offering similar features entering the fray. Zerodha has innovated by adding a “kill switch” to let heavy traders cool down and a real-time “nudge” alert about stocks that are illiquid or subject to price manipulation.

At present, with markets struggling, new account openings are down 20% from a year earlier. But the Kamaths are sticking with their marketing strategy—get clients only through word of mouth. “We’ve spent zero money on marketing while our competitors are spending a lot on customer acquisitions,” says Nikhil, the firm’s chief financial officer.

In September, the brothers started an asset management company called True Beacon offering products for ultra-high net worth individuals. They also run a mutual fund business and a non-banking financial company offering loans against securities.