Clean tech is global, with more public companies headquartered in Europe and Asia than in the United States. And some of the leaders-like Danish wind turbine maker Vestas Wind Systems and German solar panel giant Q-Cells-don't even list their shares on U.S. exchanges. This complicates things for American investors, but it is not insurmountable. As with most things that involve the exchange of information, trading foreign stocks is getting easier all the time.

Following is an overview of the currently available ways that U.S. investors can find, research, and trade foreign stocks. The more simple choices, ADRs and Pink Sheets, are detailed below. There are other options that may serve you better, but require more capital and/or expertise. Click here to read about Discount Brokers with Foreign Access, Full-Service Foreign Stock Specialists, and Global Trading Platforms

ADRs

An American Depository Receipt (ADR) is created when a U.S. bank buys a large block of stock in a foreign company and bundles the shares for reissue on a U.S. stock exchange. The stock will have a normal ticker symbol, with "ADR" appended. For example, the Yahoo! Finance listing for Japanese electronics giant Sony looks like this: SONY ADR (NYSE: SNE). Unfortunately, Sony is one of the exceptions. To qualify for an ADR listing, a foreign company must issue financial reports that conform to U.S. accounting conventions and Securities and Exchange Commission rules. Since the passage of the Sarbanes-Oxley Act in response to the corporate scandals of the 1990s, this is no simple thing. To make it worth the trouble, a company must be big and sufficiently well known to attract large numbers of U.S. investors. This limits the potential field to just a few hundred companies-and the number of those willing to list ADRs is falling rather than rising. Since the beginning of 2007, a growing list of global multinationals, including Vivendi, Suez, Groupe Danone, and LaFarge, have either delisted or announced their intent to delist their ADRs. Currently there are only a handful of major European or Asian clean tech companies with ADRs.  ....read more