** Shares of electronics firm Smartkem SMTK.O fall 22% to $1.13 premarket, just a day after notching 72% in their biggest single-day gain ever

** On Tuesday, co said it had engaged an advisory firm to explore strategic alternatives, triggering a buying frenzy and fueling retail investor optimism

** SMTK's price rose above $1 for the first time since July

** Small-cap stocks often surrender some of their gains following a sharp, retail-driven rally as momentum subsides

** Stock has lost half of its value so far this year

(Reporting by Niket Nishant in Bengaluru)

((Niket.Nishant@thomsonreuters.com))