Among the world’s biggest stock markets, there haven’t been any better investments this year than Hong Kong’s Hang Seng Index.
But under the surface of that 26 percent surge, gains are getting more concentrated — and that means for some shares, volatility is on the rise. Take one of the Hang Seng’s heaviest weighted stocks, Tencent Holdings Ltd. Its 69 percent surge this year has accounted for about a quarter of the index’s gain, according to data compiled by Bloomberg. And its 30-day volatility has jumped 51 percent, as price swings across the index grow ever more muted.