** Trading platform Webull's BULL.O shares plunge as much as 32.8%; last down 25.9% at $46.63
** Stock closed up 374.7% at $62.90 on Monday - BULL's second trading day after completing its $7.3 billion merger with blank-check firm SK Growth Opportunities Corporation
** About 37 million BULL shares changed hands on Monday, according to data compiled by LSEG
** BULL had a $29.6 billion market capital, as of last close on Monday
** Founded in 2016 by Alibaba veteran Anquan Wang, BULL's trading platform allows users to invest in stocks, exchange traded funds, cryptocurrencies and more
** St. Petersburg, Florida-based BULL caters to more than 23 million users globally
(Reporting by Arasu Kannagi Basil in Bengaluru)
((ArasuKannagi.Basil@thomsonreuters.com;))