An Investor can receive income from this source when the bonds purchased at discount are held up to maturity or when he sells the bond before maturity date at a price above the purchase price. For example, an Investor purchases a Rs.100.00 par value bond for Rs.95.40. At the time of maturity, there would be a capital gain of Rs.4.60 (Rs.100.00 - Rs.95.40). Let us say that the purchase price is more than par value; then the investor would bear capital loss. For example, assume that the investor purchased bond at Rs.105.40 i.e. more than par value. In this case investor will bear Rs.5.40 (Rs.105.40 - Rs.100.00) capital loss.
In the case of a callable bond the investor has a capital gain when the call price is more than the purchase price of the bond. For example, assume that the bond given in the previous example is called at the Rs.100.95. Then, the capital gain will be Rs.6.10 (Rs.101.50 - Rs.95.40). If the call price is less than the purchase price then the investor will bear capital loss. For example, assume that in place of Rs.100.95, the call price is Rs.93.20. In this case the investor will bear a loss of Rs.2.20 (Rs.95.40 - Rs.93.20).
In case the bond is sold before maturity or call, there will be capital gain only if the sale price is more than the purchase price. For example, assume that the bond in the above example is sold at a price of Rs.102.00. The capital gain would then be Rs.6.60 (Rs.102.00 - 95.40). If the sale price is less than the purchase price then the investor will bear capital loss. For example, assume that the bond given above is sold at Rs.94.90. In such a situation, the capital loss will be Rs.0.50 (Rs.95.40 - Rs.94.90).