Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to...

Standard Fama-French and Carhart models produce economically and statistically significant nonzero alphas, even for passive benchmark indices such as the S&P 500 and Russell 2000. We find that these alphas arise primarily from the disproportionate weight the Fama-French factors place on small...

We provide new empirical evidence suggesting that the marginal investor in mutual funds behaves differently across market conditions. If the marginal investor allocates capital across mutual funds rationally, then the relative performance of funds should be unpredictable. We find however that...

A key result of the Capital Asset Pricing Model (CAPM) is that the market portfolio---the portfolio of all assets in which each asset's weight is proportional to its total market capitalization---lies on the mean-variance efficient frontier, the set of portfolios having mean-variance...

Academic and practitioner research yields a proliferation of methods using size and value/growth attributes or factors to evaluate portfolio performance. We assess the relative merits of several of the most widely-used procedures, including variants of matched-characteristic benchmark portfolios...

We document that the observed persistence amongst the worst performing actively managed mutual funds is attributable to funds that have performed poorly both in the current and prior year. We demonstrate that this persistence results from an unwillingness of investors in these funds to respond...

We conjecture that a mutual fund manager with superior stock selection ability is more likely to benefit from trading in stocks affected by information-events. Taking the probability of informed trading (PIN, Easley, Kiefer, O'Hara, and Paperman, 1996) to measure the amount of informed trading...

Short-rebate fees are a strong predictor of the cross-section of stock returns, both gross and net of fees. We document a large "shorting premium": the cheap-minus-expensive-to-short (CME) portfolio of stocks has a monthly average gross return of 1.43%, a net return of 0.91%, and a 1.53%...

Founded in 1441, King's College was one of Cambridge University's wealthiest Colleges, endowed with a vast agricultural portfolio. John Maynard Keynes was appointed bursar just after WWI and initiated a major reallocation to equities, an innovation at least as radical as the late 20th century...

We develop a model of financially constrained arbitrage, and use it to study the dynamics of arbitrage capital, liquidity, and asset prices. Arbitrageurs exploit price discrepancies between assets traded in segmented markets, and in doing so provide liquidity to investors. A collateral...