The VPIN metric (Easley et al. 2012b) aims to detect and predict the toxicity of order flow. This paper examines the sensitivity and robustness of VPIN to the choice of trade classification scheme, which is the major input used to compute VPIN. We compare deterministic trade-by-trade classification approaches with results computed using a newly proposed heuristic approach, bulk volume classification. We find substantial differences for all levels of aggregation: trade classification, order imbalance, VPIN and identifying “toxic periods”. We also find that the detection of toxic periods does not yield consistent results in more than 60% of cases. But regression analysis can identify volume and return volatility as parameters that contribute to higher levels of sensitivity.

This paper analyzes the risk dynamics surrounding convertible bond offerings (CBOs) and Seasoned Equity Offerings (SEOs). As convertible bonds are commonly believed to be very effective at mitigating adverse selection or overinvestment problems we would expect differing risk and return patterns for convertible bond and seasoned equity issuers. By analyzing 1148 convertible bond offerings and comparing them to 2905 seasoned equity offerings, we show however that for both issuer types the systematic risk increases prior to issuance and drops sharply thereafter. This result is consistent with the notion of exercising real options, as growth options are always riskier than the underlying assets and exercising them at issuance causes an immediate drop in risk. The real option framework and the proposed dynamics of systematic risk also provide a rational explanation for the negative announcement effect, as well as any long-term underperformance subsequent to the CBO and the SEOs.