International ETF questions

As ETF's (exchange trade-fund) become widely available for sectors, countries, indexes, commodities, they essentially are involved all domain in investment world. Their volumn also has exploded dramatically lately. But there are questions regarding to how they work even tons of documents telling their stories. Now we just focus on international ETF's.

ETF's have pricing and arbitraging machnism to ensure the funds' value matches the NAV (net asset value). The insurance relies heavily on the intra-day intrinsic value (IIV) evaluation so that ETF's market retail price would fluctutate but still match to the NAV. That sounds solid. What if the ETF's are targeting to other countries' industries, e.g., Asian and European companies. Since ETF's are traded in the States while their targeting markets open in different time zones. How the IIV would work? There is no "real-time" arbitraging machnism.

Is there opportunty to be explored? Certainly. We can actually trace some international ETF's performance versus the underline industries and found relationship. For example, let's look at FXI/FXP versus Chinese market. That will reveal close correlation but the most important, it provides ahead indicators. This finding is very valuable and profitable.