(Updates, adds stock action, valuation metrics)
** Lululemon Athletica Inc shares slide 24 pct, on track for worst day since 2008 after co's Q4 earnings miss and Q1 comp store sales warning. Stock's busiest day ever with volume approaching 38 mln shares, 21x the 30-day avg
** Shares last down to $51.00, lowest point since Dec 2015, after the Canadian yoga and leisure apparel retailer said hurt by everything from a strong Canadian dollar to "clothes lacking depth and color for spring"
** Stock had closed at $66.30 on Weds after rising 4 pct in regular session
** Multiple brokerages cut their price targets and ratings on the stock after the news. Citi cut rating to neutral from buy, Susquehanna cut rating to neutral from positive, Wells Fargo drops to market perform
** Cowen, Jefferies, JPMorgan and Mizuho among others also cut price targets on the stock
** Ahead of Thurs, LULU's forward PE valuation did not appear stretched, trading at 25x vs 5-yr avg of 29x, according to Thomson Reuters Datastream
** Loss on Thurs leaves LULU down 22 pct in 2017 and down a quarter over past 12 months