Momentum and Capital Structure in the Australian Stock Market

Although there is broad consensus on a robust momentum effect in Australia, the interaction between momentum and capital structure has been underexplored in the literature. This paper explicitly examines whether capital structure promotes momentum trading in the Australian stock market. The data sample includes over 1800 stocks listed on the Australian Stock Exchange from 2000 to 2023. We construct momentum portfolios using the monthly rolling and overlapping techniques. Two ratios are calculated to measure the firms' capital structure: the book-value and market-value financial leverages. Irrespective of the capital structure measure, the superior returns of the Winner quintile are concentrated in highly leveraged stocks. In contrast, the high-leverage Loser performs worst among the Loser quintile. The return of momentum strategy enhanced with capital structure is more than 1.5 times the original momentum profit. The risk-adjusted analysis paints a similar return pattern. Additionally, we observe high volatility in earnings and cash flows for highly leveraged stocks, leading to significant mispricing. Thus, the interaction between momentum and capital structure may stem from increased misvaluation, consistent with a behavioral explanation.