New Delhi, May 25 -- As the Indian rupee slides toward the psychologically crucial 100-per-dollar mark, foreign portfolio investors (FPIs) are starting to question not just the currency's trajectory but also the Reserve Bank of India's silence on how far it is willing to let the currency fall.

Adding to the pressure, the appeal of Indian assets is fading as the gap between domestic yields and those in developed markets narrows, stripping away the high-return advantage that once drew global capital, experts told Mint.

At meetings held alongside Macquarie's Asia Conference in Hong Kong last week, several FPIs said the rupee's persistent depreciation was making them reluctant to increase exposure to Indian assets, Suresh Ganapathy, managin...