Probably an anglicism. The question is what. Perhaps comes from stock (storage, stocks) whose graphic the Spanish version is stock and its verbal form stock. Also can come from stalk (stalk, especially in a hunt), although its shape stock (Note: Spanish language does not make a noticeable difference to the pronunciation of vowels between these two words in English) or its also derived stock is recommended n. In all cases there are many synonyms in Spanish and with subtle variations of these words, which do not justify their use nor as neologisms.
