Nomura Instinet analyst Harry Curtis notes that cruise stocks are lower today following the bankruptcy filing by Thomas Cook, which he believes is due to fears about the industry's financial exposure to the U.K. firm. However, the industry's exposure is "insignificant" as cruise bookings for Thomas Cook are "miniscule" relative to the firm's air and hotel businesses, said Curtis. Royal Caribbean (RCL) booked only 20,000-25,000 passengers per year through Q3 and Norwegian Cruise Line's (NCLH) exposure is even smaller, at roughly 2,000 bookings, according to Curtis, who said both were paid in cash at or before sailing. The analyst recommends using today's pullback as an opportunity to accumulate shares of those two cruise line operators. In afternoon trading, Royal Caribbean shares are down 2%, Norwegian shares are down 1% and industry peer Carnival (CCL) has fallen 2%.