To be sure, the Sensex’s advance is being driven by only a handful of stocks, a sign of its potential fragility. Two, in particular, Reliance Industries Ltd. and ICICI Bank Ltd., account for about half the measure’s gain. Some 14 of the gauge’s 31 members, or about 45 per cent, have posted declines this year. But it’s not as if India’s 13 per cent rally this year is that different from what’s happening elsewhere in the world. Many stock markets have had double-digit percentage increases even as economic fundamentals weaken. A global benchmark of developing and emerging-market equities is trading just below an all-time high despite concerns over global growth and the trade war between the US and China.