Reasons why DBS can't be knocked off top spot

Return on equity is pegged at 11.2%.

According to CIMB, DBS trades at 1.08x CY13 P/BV for a market implied ROE of 10.3%. We think this severely understates its fee-income strength. We forecast a CY13 ROE of 11.2%. 

The firm thinks DBS will be a key beneficiary of rising interest by tapping debt-capital markets in Singapore. Investment-banking fees should hold up in 2013.

In addition, DBS could benefit from an improving Chinese economy. Trade-financing fees could hold up. Of the three banks, DBS has made the most headway in trade financing in China.

Here's more from CIMB:

Lastly, its NIM could enjoy the greatest uplift in 2013. Its deposit strength and comfortable LDR position suggest less pressure in shoring up precious deposits in a rising LDR environment.

Having rolled out its new enterprise banking platform, DBS could continue to make headway in the higher-margin SME space in 2013. Coupled with a potential increase in asset yields, assuming rational competition, its NIM improvement could beat that of peers, in our estimation.

Our DDM-based target price of S$17.36 (r: 9.8%, g: 4.2%) is unchanged and implies 1.27x CY13 P/BV.