** Online wellness firm Oddity Tech's ODD.O shares plunge 40.8% to $17.17 premarket
** Co expects Q1 revenue to decline 30% year-on-year due to higher costs for customer acquisition
** Says it experienced a dislocation with its largest ad partner, driven by algorithm changes
** Co says it has identified the root cause of the problem and expects acquisition costs to return to normal levels in Q3 and Q4
** ODD's Q4 revenue of $153 mln beat analysts' estimate of $151 mln - data compiled by LSEG
** ODD stock down 27.8% YTD as of last close after declining 4.4% in 2025
(Reporting by Utkarsh Tushar Hathi)
((utkarshtushar.hathi@thomsonreuters.com))