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Return Dynamics, Volatility, Tail Risk

Paper Session

Saturday, Jan. 3, 2026 2:30 PM - 4:30 PM (EST)

Loews Philadelphia Hotel, Commonwealth Hall D
Hosted By: American Finance Association
  • Jessica Wachter, University of Pennsylvania

The number of listed firms, creative destruction, and idiosyncratic volatility

Sohnke Bartram
,
University of Warwick
Gregory Brown
,
University of North Carolina-Chapel Hill
Rene Stulz
,
Ohio State University

Abstract

Idiosyncratic volatility (IV) increases with the number of listed firms. This finding holds for aggregate, industry, and firm IV. We explain the relation between idiosyncratic volatility and the number of listed firms through Schumpeterian creative destruction. We show that, within an industry, Schumpeterian crea-tive destruction increases as the number of listed firms increases. Further, innovation in an industry in-creases with the number of listed firms. Controlling for changes in the number of listed firms, aggregate and industry IV are weakly positively related to the number of non-listed firms.

Equity Premium Events

Ben Knox
,
Federal Reserve Board
Mehrdad Samadi
,
Rutgers University
Juan m. Londono
,
Federal Reserve Board
Annette Vissing-Jorgensen
,
Federal Reserve Board

Abstract

We develop a methodology to determine which days are ``equity premium events': events with significantly elevated equity premia relative to the daily equity term structure. To do so, we use recently available daily S&P 500 option expirations and forward analogs of option-implied ex ante measures of the equity premium. We use a data-driven approach to identify events that are significantly priced without taking a stance on what those events are. A variety of individual events are associated with significantly elevated equity premia. Among macroeconomic releases, FOMC, CPI, and nonfarm payrolls have the largest abnormal equity premia, which increase substantially between June 2022 and June 2023. However, the elevated equity premia on macroeconomic release days account for a significantly smaller share of total expected returns compared to previous estimates using realized excess returns. Political events explain some of the largest equity premium days in our sample, but they contribute less to total equity premium due to their lower frequency. To provide intuition for the significant variation in equity premia across announcement types and time, we propose an asset pricing framework that decomposes the equity premium for a given macroeconomic release into components due to news variance and the sensitivities of the stock market and the SDF to the news released.

Parameter Learning, Tail Risks, and Risk Premia Decomposition

Mykola Babiak
,
Lancaster University
Roman Kozhan
,
University of Warwick

Abstract

We examine the decomposition of equity and variance premiums on the state space of market returns. Empirically, we show that low but non-disastrous returns are the primary drivers of both risk premia, while left-tail returns have a stronger influence on the variance premium. Theoretically, we propose a production economy with uncertain transition probabilities in two-state regime-switching productivity growth. Rationally pricing parameter uncertainty is crucial for explaining novel decompositions while simultaneously capturing salient features of index option prices, equity returns, variance, and macroeconomic quantities. Intuitively, rational pricing of beliefs amplifies the impact of shocks, generating physical tail risks in the economy.

Seeking Gamma: Lessons from the Meme Frenzy

Gulnara Zaynutdinova
,
West Virginia University
Cuyler Strong
,
Wayne State University
Ahmed Baig
,
Boise State University

Abstract

There has been substantial debate about the existence and impact of a gamma squeeze during the GameStop price surge in January 2021. We provide novel empirical evidence confirming that a gamma squeeze indeed occurred and suggest that this squeeze started earlier than previously documented, in the Fall of 2020. We also identify other gamma squeeze episodes across a broader set of meme stocks during the same time period. Extending our analysis beyond meme stocks to all U.S. stocks, we systematically identify 669 potential gamma squeeze events from 2019 to 2023. These gamma squeezes result in economically significant price impacts, generating an average cumulative abnormal return of 5.13% in the month following their initiation. Our findings offer valuable insights for researchers, regulators, and market participants.

Discussant(s)
Thomas Winberry
,
University of Pennsylvania
Jun Pan
,
Shanghai Jiao Tong University
Lars Lochstoer
,
University of California-Los Angeles
Robert Battalio
,
University of Notre Dame
JEL Classifications
  • G1 - General Financial Markets