Eliminating Biases in Evaluating Mutual Fund Performance from a Survivorship Free Sample

Poor performing mutual funds are less likely to be observed in the data sets that are typically available. This so-called survivor problem can induce a substantial bias in measures of the performance of the funds and the persistence of this performance. Many studies have recently argued that survivorship bias can be avoided by analyzing a sample that contains returns on each fund up to the period of disappearance using standard techniques. Such data sets are usually referred to as 'survivorship free'. In this paper we show that the use of standard methods of analysis on a 'survivorship free' data-set typically still suffers from a bias and we show how one can easily correct for this using weights based on probit regressions. Using a sample with quarterly returns on U.S. based equity funds, we first of all model how survival probabilities depend upon historical returns, the age of the fund and upon aggregate economy-wide shocks. Subsequently we employ a Monte Carlo study to analyze the size and shape of the survivorship bias in various performance measures that arise when a 'survivorship free database' is used with standard techniques. In particular, we show that survivorship bias induces a spurious U-shape pattern in performance persistence. Finally, we show how a weighting procedure based upon probit regressions can be used to correct for the bias. In this way, we obtain bias-corrected estimates of abnormal performance relative to a one-factor and the Carhart [1997] four-factor model, as well as its persistence. Our results are in accordance with the persistence pattern found by Carhart [1997], and do not support the existence of a hot hand phenomenon in mutual fund performance.

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Multi-messenger Observations of a Binary Neutron Star Merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

Behavioral Preferences for Individual Securities: The Case for Call Warrants and Call Options

Since 1998, large investment banks have flooded the European capital markets with issues of call warrants.This has led to a unique situation in the Netherlands, where now call warrants, traded on the stock exchange, and long-term call options, traded on the options exchange, exist.Both entitle their holders to buy shares of common stock.We use the long-term call options in order to price the call warrants.Using the model of Black and Scholes (1973), the Square Root model version of the Constant Elasticity of Variance model of Cox and Ross (1976), and the Binomial model of Cox et al.(1979) we find that the call warrants are strongly overvalued durin the first five tradin days.The average overvaluation is between 25 and 30 percent for all three models.Only a small part of this overvaluation can be explained by rational arguments such as transaction costs.We conclude that the overvaluation can be attributed to a behavioral preference of private investors for call warrants.

Evaluating Style Analysis

In this paper we analyze the use and implications of (return based) style analysis. First, style analysis may be used to estimate the relevant factor exposures of a fund. We use a simple simulation experiment to show that imposing portfolio and positivity constraints in style analysis leads to significant efficiency gains if the factor loadings are indeed positively weighted portfolios, in particular when the factors have low cross-correlations. If this is not the case though, imposing the constraints can lead to biased exposure estimates. Second, style analysis may be used in performance measurement. If the actual factor exposures are a positively weighted portfolio and if the risk free rate is one of the benchmarks, then the intercept coincides with the Jensen measure. In general, the intercept in the style regression can only be interpreted as a special case of the familiar Jensen measure. Third, style estimates may be compared with actual portfolio holdings. We show that the actual portfolio holdings will in general not reveal the actual investment style of a fund because of cross exposures between the asset classes and because fund managers may hold securities that on average do not have a beta of one relative to their own asset class. Although return based style analysis is less suitable to predict future portfolio holdings, our empirical analysis suggests that it performs better than holding based style analysis in predicting future fund returns

Evaluating Style Analysis

In this paper we evaluate applications of (return based) style analysis. The portfolio and positivity constraints imposed by style analysis are useful in constructing mimicking portfolios without short positions. Such mimicking portfolios can be used e.g. to construct efficient portfolios of mutual funds with desired factor loadings if the factor loadings in the underlying factor model are positively weighted portfolios. Under these conditions style analysis may also be used to determine a benchmark portfolio for performance measurement. Attribution of the returns on portfolios of which the actual composition is unobserved to specific asset classes on the basis of return based style analysis is attractive if moreover there are no additional cross exposures between the asset classes and if fund managers hold securities that on average have a beta of one relative to their own asset class. If such restrictions are not met, and in particular if the factor loadings do not generate..