HDFC Bank's key metrics are expected to improve over the next 12 to 15 months, leading to a re-rating of the stock. The bank's net interest margins have likely reached their lowest point and will gradually improve. The challenge remains the high credit deposit ratio, but loan growth is expected to normalize it gradually. Currently, the bank lacks differentiating factors compared to its peers, but once all key metrics align, there is potential for outperformance in the stock.