Tarjetas | Mejores ofertas bancarias. Buy vs. Long | Sell vs. Short | Understanding Key Terms | TradeKing. You’ll notice sometimes an investor or trader may use the word “buy” while others use the word “long.” What’s the difference? It could be very little, or a lot, all at the same time. Buying a stock (or an option) is straightforward. It’s the resulting position which might not be obvious. Consider another example: you are short 100 shares of Ginormo Industries and then you buy 100 shares of the same stock. The same distinctions can apply to “selling” versus “short”. MegaBolsa.com :: Bolsa, Finanzas, Mercados, Inversión :: Análisis, Noticias, Cotizaciones, Divisas, Valores. SmartStops - Home.