DBS has the option to redeem the preference shares in 2020 and pay back the shareholders. They will do so, if they find that the interest rate is low and they can refinance the preference shares at lower cost. However, if interest rate goes up high, they are likely to keep the preference shares beyond 2020.
The preference shareholder can sell the shares at any time through the stockmarket, at the prevailing market price. The price will increase above par, if the market interest rate has dropped. the price will decrease if the market interest rate increases.
I have asked a financial expert to make a brief analysis and post the details in the FISCA website (www.fisca.sg). It will be available to FISCA members after login.