Alıntı:
Rule of Thumb
I find that I typically pay an extra $50 per trade for a foreign stock compared to an ADR. I generally hold stocks for one to five years. Since there is also a similar fee to sell the stock, I will generally pay an extra $100 to buy and sell a foreign stock. Annual ADR fees seem to usually be around 1% of the share price, so if I can make a trade large enough to keep the extra commission paid less than 1% and hold the stock longer than a year, it makes sense to buy the foreign stock rather than the ADR.
As a formula, I buy the foreign stock if
D x Y > 100 x C
Where D is the size of the trade in dollars (500 shares at $10 is $5,000), Y is the number of years I expect to hold the stock or ADR, and C is the extra commission I have to pay to buy the foreign stock. Since my expected holding time is typically stocks is 2 years or more and I usually pay an extra $50 to trade foreign stocks, the foreign stock purchase will usually make sense for trades of $3,000 or more.
In general, I dislike ADR fees, so I try to buy foreign stocks using large trades.