The sum of the intercept and the residuals in (1), call it RMO, is a zero investment portfolio return that is uncorrelated with the four explanatory variables in (1). We can use RMO as an orthogonalized market factor that captures common variation in returns left by SMB, HML, TERM, and DEF. Since the stock-market returns, SMB and HML, are largely uncorrelated with the bond-market returns, TERM and DEF (table 2), five-factor regressions that use RMO, SMB, HML, TERM, and DEF to explain bond and stock returns will provide a clean picture of the separate roles of bond- and stock-market factors in bond and stock returns. The regressions are in table 8.