We propose a protocol for identifying genuine risk factors. A genuine risk factor must be related to the covariance matrix of returns, must be priced in the cross-section of returns, and should yield a reward-to-risk ratio that is reasonable enough to be consistent with risk pricing. A market...

We propose a protocol for identifying genuine risk factors. The underlying premise is that a risk factor must be related to the covariance matrix of returns, must be priced in the cross-section of returns, and should yield a reward-to-risk ratio that is reasonable enough to be consistent with...

Changing expected returns can induce spurious autocorrelation in returns. We show why this happens with simple examples and investigate its prevalence in actual equity data. In a key contribution, we use shifts in ex ante expected return estimates from options prices, factor models, and...

Movements in expected returns (ER) can cause a bias in measured autocorrelations, and the resulting spurious component is positive for infrequent regime shifts. We demonstrate this point analytically and investigate its empirical prevalence. In a key contribution, we use shifts in ex ante ER...