Mark Grinblatt

Do industries explain momentum

This paper documents a strong and prevalent momentum effect in industry components of stock returns which accounts for much of the individual stock momentum anomaly. Specifically, momentum investment strategies, which buy past winning stocks and sell past losing stocks, are significantly less profitable once we control for industry momentum. By contrast, industry momentum investment strategies, which buy stocks from past winning industries and sell stocks from past losing industries, appear highly profitable, even after controlling for size, book-to-market equity, individual stock momentum, the cross-sectional dispersion in mean returns, and potential microstructure influences. Copyright The American Finance Association 1999.

Mutual Fund Performance: An Analysis of Quarterly Portfolio Holdings

This article employs the 1975-84 quarterly holdings of a sample of mutual funds to construct an estimate of their gross returns. This sample, which is not subject to survivorship bias, is used in conjunction with a sample that contains the actual (net) returns of the mutual funds. In addition to allowing the authors to estimate the bias in measured performance that is due to the survival requirement and to estimate total transaction costs, the sample is used to test for the existence of abnormal performance. The tests indicate that the risk-adjusted gross returns of some funds were significantly positive. Copyright 1989 by the University of Chicago.

How Distance, Language, and Culture Influence Stockholdings and Trades

This paper documents that investors are more likely to hold, buy, and sell the stocks of Finnish firms that are located close to the investor, that communicate in the investor’s native tongue, and that have chief executives of the same cultural background. The inf luence of distance, language, and culture is less prominent among the most investment-savvy institutions than among both households and less savvy institutions. Regression analysis indicates that the marginal effect of distance is less for firms that are more nationally known, for distances that exceed 100 kilometers, and for investors with more diversified portfolios.

Performance Measurement without Benchmarks: An Examination of Mutual Fund Returns

This article introduces a new measure of portfolio performance and applies it to study the performance of a large sample of mutual funds. In contrast to previous studies of mutual fund performance, the measure used in this study employs portfolio holdings and does not require the use of a benchmark portfolio. It finds that the portfolio choices of mutual fund managers, particularly those that managed aggressive growth funds, earned significantly positive risk-adjusted returns in the 1976-85 period. Copyright 1993 by University of Chicago Press.

The Valuation Effects of Stock Splits and Stock Dividends

This study presents evidence which indicates that stock prices, on average, react positively to stock dividend and stock split announcements that are uncontaminated by other contemporaneous firm-specific announcements. In addition, it documents significantly positive excess returns on and around the ex-dates of stock dividends and splits. Both announcement and ex-date returns were found to be larger for stock dividends than for stock splits. While the announcement returns cannot be explained by forecasts of imminent increases in cash dividends, the paper offers several signalling based explanations for them. These are consistent with a cross- sectional analysis of the announcement period returns.

A Study of Monthly Mutual Fund Returns and Performance Evaluation Techniques

This paper empirically contrasts the Jensen Measure, the Positive Period Weighting Measure, developed in Grinblatt and Titman (1989b), and a measure developed from the Treynor-Mazuy (1966) quadratic regression on a sample of 279 mutual funds and 109 passive portfolios, using a variety of benchmark portfolios. The study finds that the measures generally yield similar inferences when using the same benchmark and that inferences can vary, even from the same measure, when using different benchmarks. This paper also analyzes the determinants of mutual fund performance. Tests of fund performance that employ fund characteristics, such as net asset value, load, expenses, portfolio turnover, and management fee are reported. These tests surprisingly suggest that turnover is significantly positively related to the ability of fund managers to earn abnormal returns.

Predicting stock price movements from past returns: the role of consistency and tax-loss selling

The consistency of positive past returns and tax-loss selling significantly affects the relation between past returns and the cross-section of expected returns. Analysis of these additional effects across stock characteristics, seasons, and tax regimes provides clues about the sources of temporal relations in stock returns, pointing to potential explanations for this relation. A parsimonious trading rule generates surprisingly large economic returns despite controls for confounding sources of return premia, microstructure effects, and data snooping biases.

Factor pricing in a finite economy

Abstract Prior theoretical derivations of the Arbitrage Pricing Theory (APT) bound an aggregate measure of the deviation of mean asset returns from that predicted by a linear pricing equation. It is conceivable, given this bound, that some assets might be badly mispriced by the model. In this paper, a more intuitive derivation of the factor pricing equation is presented which describes the deviation on an asset by asset basis. The deviation is shown to be small for assets in a realistic finite economy and is arbitrarily close to zero for those assets with arbitrarily small size relative to aggregate wealth. It follows that the linear pricing equation provides a good approximation for the mean returns of all traded assets.

Neural and behavioral bases of age differences in perceptions of trust

Older adults are disproportionately vulnerable to fraud, and federal agencies have speculated that excessive trust explains their greater vulnerability. Two studies, one behavioral and one using neuroimaging methodology, identified age differences in trust and their neural underpinnings. Older and younger adults rated faces high in trust cues similarly, but older adults perceived faces with cues to untrustworthiness to be significantly more trustworthy and approachable than younger adults. This age-related pattern was mirrored in neural activation to cues of trustworthiness. Whereas younger adults showed greater anterior insula activation to untrustworthy versus trustworthy faces, older adults showed muted activation of the anterior insula to untrustworthy faces. The insula has been shown to support interoceptive awareness that forms the basis of “gut feelings,” which represent expected risk and predict risk-avoidant behavior. Thus, a diminished “gut” response to cues of untrustworthiness may partially underlie older adults’ vulnerability to fraud.

Social Influence and Consumption: Evidence from the Automobile Purchases of Neighbors

This study analyzes the automobile purchase behavior of all residents of two Finnish provinces over several years. Using a comprehensive data set with location coordinates at the individual consumer level, it finds that the purchases of neighbors, particularly in the recent past and by those who are geographically most proximate, influence a consumers purchases of automobiles. There is little evidence that emotional biases, like envy, account for the observed social influence on consumption. Copyright by the President and Fellows of Harvard College and the Massachusetts Institute of Technology.