{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T20:11:31Z","timestamp":1786738291428,"version":"build-2736575974"},"posted":{"date-parts":[[2026]]},"group-title":"SSRN","reference-count":0,"publisher":"Elsevier BV","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>Using NASDAQ TotalView Level 3 data for 20 stocks, I document how order book microstructure changed during the April 2025 Liberation Day tariff shock. Trading volume doubled (+101%), but the composition of order flow shifted dramatically: median order lifetime collapsed from 120ms to 32ms (-73%), the share of sub-millisecond orders rose 18%, and cancel-to-trade ratios fell 27%. These patterns are consistent with a regime shift from patient liquidity provision to aggressive, short-lived order placement. The effect is heterogeneous: smaller-cap stocks (CMCSA: +478%, CSCO: +357%) experienced proportionally larger order flow surges than mega-caps (TSLA: +21%, NFLX: +56%). These findings provide the first nanosecond-resolution evidence on how a major trade policy shock transforms limit order book dynamics.<\/jats:p>","DOI":"10.2139\/ssrn.6562258","type":"posted-content","created":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T16:14:10Z","timestamp":1776701650000},"source":"Crossref","is-referenced-by-count":0,"title":["Order Book Dynamics During the Liberation Day Tariff Shock: Evidence from 20 NASDAQ Stocks"],"prefix":"10.2139","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-8477-9393","authenticated-orcid":true,"given":"Boon Chuan","family":"Lim","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"78","container-title":[],"original-title":[],"deposited":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T19:18:47Z","timestamp":1786735127000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ssrn.com\/abstract=6562258"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026]]},"references-count":0,"URL":"https:\/\/doi.org\/10.2139\/ssrn.6562258","relation":{},"subject":[],"published":{"date-parts":[[2026]]},"subtype":"preprint"}}