This paper estimates the performance of insider trades on the closely held Oslo Stock Exchange (OSE) during a period of lax enforcement of insider trading regulations. Our data permit construction of a portfolio that tracks all movements of insiders in and out of the OSE firms. Using three alternative performance estimators in a time-varying expected return setting, we document zero or negative abnormal performance by insiders. The results are robust to a variety of trade characteristics. Applying the performance measures to mutual funds on the OSE, we also document some evidence that the average mutual fund outperforms the insider portfolio.

We find that the underperformance of IPO stocks relative to the market over a three-year holding period is less severe for IPOs handled by more prestigious underwriters. Consistent with prior studies, we also find that IPOs managed by more reputable underwriters are associated with less short-run underpricing. Among the various existing proxies for underwriter reputation, the Carter–Manaster measure is the most significant in the context of initial returns and also in the context of the three-year performance of IPOs. The study also provides an updated list of the Carter–Manaster measure for various underwriters.

We find that the underperformance of IPO stocks relative to the market over a three‐year holding period is less severe for IPOs handled by more prestigious underwriters. Consistent with prior studies, we also find that IPOs managed by more reputable underwriters are associated with less short‐run underpricing. Among the various existing proxies for underwriter reputation, the Carter–Manaster measure is the most significant in the context of initial returns and also in the context of the three‐year performance of IPOs. The study also provides an updated list of the Carter–Manaster measure for various underwriters.

This paper estimates the performance of insider trades on the closely held Oslo Stock Exchange (OSE) during a period of lax enforcement of insider trading regulations. Our data permit construction of a portfolio that tracks all movements of insiders in and out of the OSE firms. Using three alternative performance estimators in a time‐varying expected return setting, we document zero or negative abnormal performance by insiders. The results are robust to a variety of trade characteristics. Applying the performance measures to mutual funds on the OSE, we also document some evidence that the average mutual fund outperforms the insider portfolio.