** U.S.-listed shares of drug developer ORPH.O tumble
52.5% to $9.97 premarket
** Stock top pct loser across U.S. exchanges before the bell
** Co says it is not aware of any material change in its
clinical development programs, financial condition or results of
operations that explains price volatility or trading volume
happened since June 10 urn:newsml:reuters.com:*:nGNE4P1SgK
** ORPH shares surged more than 1,367% to $77.77 in the
previous session, before closing up 301.5%
** About 6.2 mln shares have traded premarket, ~2,163% of
their 30-DMA volume
** In May, ORPH said its late-stage pivotal trial testing
its lead drug candidate, arimoclomol, to treat amyotrophic
lateral sclerosis (ALS) did not meet the main and secondary
goals urn:newsml:reuters.com:*:nL4N2MU35W
** Stocks popular with small-time traders on online forums,
such as Reddit's WallStreetBets, has been on a run recently,
spurring wild swings in certain stocks; most notably prompting a
short squeeze in GameStop Corp GME.N earlier this year
urn:newsml:reuters.com:*:nL3N2NR3UD
(Reporting by Devik Jain in Bengaluru)
((Devik.Jain@thomsonreuters.com; within U.S. +1 646 223 8780;
outside U.S. +91 80 6182 2062; ;))