• A market maker is a market participant that offers liquidity, typically both on the buy side by placing bid orders and on the sell side by placing offer orders. A market maker meets imbalances in supply and demand for shares caused by idiosyncratic trade orders from anxious traders. Typically, the market maker’s purpose for providing liquidity is to earn the spread between the bid and offer prices by buying at the bid price and selling at the offer price.
• The test is a joint hypothesis of the appropriateness of the particular model of returns (in determining what constitutes an abnormal return) and a test of whether a particular investment has generated statistically significant abnormal returns.
• Standardized unexpected earnings (SUE) is a measure of earnings surprise, with some measure of unexpected earnings in the numerator and some measure of earnings volatility in the denominator.
• There is evidence that positive or negative net stock issuance is one of the most profitable anomalies. Companies that issue large amounts of new shares, such as more than 20% of the shares currently outstanding, frequently see their stock price substantially underperform the market.
• The information coefficient, which measures managerial skill as the correlation between managerial return predictions and realized returns
• Nonactive bets are positions held to reduce tracking error rather than to serve as return-enhancing active bets. In other words, these are not active bets in the sense that they are intended to add alpha to the portfolio; rather, they are added to keep the active manager’s return from straying too much from the benchmark.
• Multiple-factor scoring models, which combine the factor scores of a number of independent anomaly signals into a single trading signal.
• The limits to arbitrage, which refers to the potential inability or unwillingness of speculators, such as pairs traders, to hold their positions without time constraints or to increase their positions without size constraints. Very large positions with high degrees of leverage increase the probability of financial ruin and the inability to survive short-term displacements.
• Mean neutrality is when a portfolio is shown to have zero beta exposure or correlation to the underlying market index. In other words, when the market experiences a move in one direction, mean-neutral portfolios are no more likely to move in the same direction as in the opposite direction. Variance neutrality is when portfolio returns are uncorrelated to changes in market risk.