I analyze the recent experience of unconventional monetary policy in Sweden to study the interest rate transmission mechanisms of government bond purchases when interest rates are away from the lower bound. Using dynamic term structure models and event study regressions I find that government bond purchases have important portfolio balance and signaling effects. The signaling channel operates mainly by lowering short-rate expectations in the intermediate segment of the yield curve, while the portfolio balance channel is effective in lowering longer maturity term premia. In addition, I find that target interest rate policy and government bond purchases operate in different segments of the yield curve. This suggests that a combination of the two policies can be used to lower interest rates across the whole maturity spectrum, making monetary policy more expansionary.