spb/wp15_uqo

1\documentclass[11pt]{letter}2\usepackage[margin=1.2in]{geometry}3\signature{Simon-Pierre Boucher\\Universit\'e du Qu\'ebec en Outaouais}4\begin{document}5\begin{letter}{The Editors\\International Review of Financial Analysis}6\opening{Dear Editors,}78Please consider the enclosed manuscript, ``Faster, Wider, More Fragile? The9Evolution of Intraday Shock Propagation in U.S. Equity Markets, 1992--2026,''10for publication in the \emph{International Review of Financial Analysis}.1112The paper measures how idiosyncratic intraday shocks travel across the U.S.13equity cross-section using 7.7 billion one-minute bars spanning thirty-four14years, including delisted securities. Its three findings are, we believe, of15direct interest to the journal's readership: (i) isolated six-sigma16one-minute shocks raise market-wide tail activity by at most a few percent of17its base rate relative to 1.8 million matched within-stock placebos, in any18decade; (ii) propagation is instead concentrated in the shocked stock's19lagged-correlation neighborhood, and this network channel roughly tripled20between the floor-trading and algorithmic eras; and (iii) common information21is impounded within the minute, ordinary extreme minutes became an order of22magnitude rarer after decimalization, and severe co-jump minutes are roughly23ten times more frequent in 2008 and 2020 than in calm years. The manuscript24reports the design diagnostics that bound each of these statements.2526The analysis is fully reproducible: the data snapshot is pinned by checksum,27every headline number in the manuscript is generated programmatically from28machine-readable results, and replication code accompanies the submission.29The manuscript is not under consideration elsewhere, and there are no30competing interests to declare.3132\closing{Sincerely,}33\end{letter}34\end{document}35