India, Nov. 19 -- The listing of Billionbrains Garage Ventures Ltd., the operator of India's largest online brokerage Groww, has turned out to be a lesson in market euphoria and swift correction.

After a spectacular post-listing rally that saw Groww's share price surge over 90% from its IPO price, the high-flying stock hit a decisive 10% lower circuit today, signaling the first major wave of profit booking and revaluation of its aggressive valuation.

The initial days of trading were defined by relentless buying. Groww's shares, which had listed at a premium, sprinted past major valuation milestones, riding on its strong brand recall among India's growing cohort of retail investors and its demonstrated profitability.

The phenomenal rall...