Indian private-sector banks are also among the most richly valued. : India’s economic and credit slowdown is revealing the strengths and weaknesses of its banking sector. Roiled by unprecedented frauds and surging bad debt, the nation’s state-run banks have returned the least to investors this year. However, investors’ belief in the potential of Asia’s No. 3 economy shows in the fact that its newest lenders offer the best returns, and a clutch of private Indian banks are among the world’s most expensive.