I have hesitated to invest in securities outside Canada (i.e., in the U.S.) because of foreign-exchange risk. It doesn’t take a big change in the exchange rates to have a material impact on the investment, and I have no interest in being a speculator in foreign exchange. What is your view of investing outside Canada, and is there a way to eliminate foreign-currency risk?

Our view is that virtually all Canadian investors should have 20% to 30% of their portfolios in U.S. stocks, like the ones we recommend in Wall Street Stock Forecaster.

We feel now is a good time to hold high-quality U.S. stocks, and we see U.S. dollar exposure as a plus—a valuable form of diversification.

Another option is to add some foreign …

Poseidon Concepts, $15.53, symbol PSN on Toronto (Shares outstanding: 72.0 million; Market cap: $1.1 billion; www.poseidonconcepts.com), rents its fluid-handling tanks to over 100 customers in the oil and gas industry.

In November 2011, Open Range Energy changed its name to Poseidon Concepts after it handed out shares of its oil and gas production interests to its shareholders in November 2011. …

Medizone International, $0.20, symbol MZEI on the U.S. over-the-counter bulletin board (Shares outstanding: 269.6 million; Market cap: $53.9 million; www.medizoneint.com), has developed what it calls its AsepticSure decontamination system. This is a portable machine that cleans the air in rooms.

Medizone believes AsepticSure can purify air to a very high decontamination standard. The device could be used in facilities such …

Twin Disc, $32.71, symbol TWIN on Nasdaq (Shares outstanding: 11.6 million; Market cap: $379.4 million; www.twindisc.com), designs, makes and sells transmission equipment for boats, off-highway vehicles such as military trucks, mining trucks, firefighting and rescue vehicles, and heavy-duty equipment such as rock crushers, oil rigs and wood chippers.

The company’s products include marine transmissions, propellers and boat controls, as well …

Seaspan Corp., $16.65, symbol SSW on New York (Shares outstanding: 69.3 million; Market cap: $1.2 billion; www.seaspan.com), charters its fleet of container ships under long-term, fixed-rate contracts. These ships carry metal containers that can be easily transferred between ships, trains and trucks.

Seaspan’s fleet of 72 container ships consists of 65 vessels that are currently operating and seven that are under …

Investors often ask how we manage to recommend so many stocks that get taken over at a profit—often a major profit. This question came up again last week. With no warning, long-time recommendation Gennum Corp. attracted a takeover bid that sparked a 119% rise in its stock price in a single day.

Gennum Corp., $13.48, symbol GND on Toronto (Shares outstanding: …

Graphite has a large—and growing—number of industrial uses

Many investors are interested in graphite because it is used in the lithium-ion batteries that power electric cars. But it has a number of other profitable uses as well.

For example, in the steel industry, graphite is mainly used to strengthen the bricks that line furnaces. When added to steel itself, graphite increases …

Africa Oil, $1.68, symbol AOI on Toronto (Shares outstanding: 212.0 million; Market cap: $356.2 million; www.africaoilcorp.com), is a Canadian oil and gas exploration company with interests in properties in Kenya, Ethiopia, Somalia and Mali.

Africa Oil plans to drill seven to 10 wells over the next 18 months. The company holds cash of $118.0 million, or $0.53 a share, so it …

Arris Group, $11.75, symbol ARRS on Nasdaq (Shares outstanding: 121.2 million; Market cap: $1.4 billion; www.arrisi.com), supplies phone and cable companies with the technology they need to deliver video, data and voice services.

For example, the company supplies equipment that lets cable operators offer personal video recording (PVR) services, which let viewers record TV programs and view them when it’s convenient. …

Terex Corp., $20.41, symbol TEX on New York (Shares outstanding: 110.3 million; Market cap: $2.3 billion, www.terex.com) makes construction and mining equipment for customers in the U.S. (27% of sales), Germany (7%), the U.K. (5%), other European countries (20%) and elsewhere (41%).

Terex operates has five divisions: cranes (30% of sales); aerial work platforms (25%); construction (22%); material handling and port …