H. Wang and C. Wang [Visibility of the compass rose in financial asset returns: A quantitative study, J. Bank. Financ. 26 (2002), 1099–1111] derive a measure of the visibility of the radial patterns that appear in a plot of current and past returns, which are more commonly known as the compass rose. In theory, this measure should be positively related to the tick/volatility ratio. In practice however, we find that this relationship does not hold for higher tick/volatility ratios that are common to stock market data. Thus, the use of this measure is limited in real world applications. We propose a correction factor that improves the behaviour of the quality measure over higher tick/volatility ratios, however, further research is required to fully identify and correct the problem.

Companies planning a private placement typically gauge the interest of potential buyers before the offering is publicly announced. Regulators are concerned with this practice, called wall-crossing, as it might invite insider trading, especially when the potential investors are hedge funds. We examine privately placed common stock and convertible offerings and find evidence of widespread pre-announcement short selling. We show that pre-announcement short sellers are able to predict announcement day returns. The effects are especially strong when hedge funds are involved and when the number of buyers is high. We also observe pre-announcement trading in the options market.