Silent Killer: How Just One Stock Can Wreck It All

Concentration risk—too much exposure to one stock or sector—can make or break you

- VIRAL BHATT

When equity markets rally, portfolios with concentrated bets often look like winners. Investors in stocks like Gensol Engineering or Mazagon Dock in 2023 may have flaunted triple-digit returns. But beneath that temporary high lies a quiet but dangerous threat: concentration risk—excessive exposure to a single stock, sector, or strategy. While it can magnify gains, it also amplifies losses when things go wrong.

Temptation of overconfidence: Of late, retail investors in India have been shifting away from diversified MFs to direct stock picking. Fueled by finfluencers, demat apps, and FOMO, many investors chase winners highlighted in "top gainers in 1 year" filters. For instance, someone sees a stock that has returned 300% over 18 months and bets big, assuming the past will repeat. But markets are rarely so kind.

The Gensol Engineering lesson: The stock soared over 200% in 2023. But by early 2024, after reports of financial irregularities and broader corrections, it plunged nearly 30% in weeks. For those who had 40–50% of their portfolio in Gensol, the damage was severe—even though broader indices were stable.