A common argument is that portfolio rebalancing improves return and simultaneously reduces
risk in the long-run. Previous rebalancing studies are unable to verify this proposition using
statistical inference. We introduce a novel block bootstrap approach that enables us to test the
value added of rebalancing strategies for stock-bond portfolios using historical data from the
United States, the United Kingdom, and Germany. Analyzing the return, the volatility, and the
Sharpe ratio of different rebalancing strategies, historical simulation results indicate that rebalancing
strategies outperform a buy-and-hold strategy. While this outperformance is only of
marginal importance in terms of average returns and net asset values (NAVs), it can be primarily
attributed to a significant reduction of portfolio volatility. Based on the Sharpe ratio as
a risk-adjusted performance measure, our results further indicate that the superior performance
of rebalancing strategies compared with a buy-and-hold strategy is statistically significant
and arises from this reduced portfolio volatility. Depending on the specific stock and
bond market characteristics of the three countries under investigation, the optimal rebalancing
frequency ranges between quarterly and yearly intervals.