The column on the January Effect triggered a wide range of questions. Even though the window of opportunity is closing, we still have a few days left to explore the best way to take advantage of the seasonal rally in small-cap stocks. Steve, Do the iShares have a Web site, or do you have a link to a Web site for all their ETFs? Does one exist? --T.S. Because the article suggested buying calls on the Russell 2000 iShares ( IWM), understanding the concept, construction and offerings of the exchange traded funds known as iShares seems like a great place to start. By going to the Barclay's iShares Web site you can learn all about their products and myriad offerings, some 98 at last count, including broad-based indices, narrow sector and foreign, and bond-based funds. For example, you might decide that buying the iShares Russell 2000 Growth Index Fund ( IWO) or its options offers a better opportunity than the iShares Russell 2000 Value Index Fund ( IWN). (This is probably a good time to remind everyone to be very careful and double-check all ticker symbols before entering an order. Make sure you understand what you are trading, and that what you are trading is what you intended on trading. Is that clear?) Steve, I saw a quote that read IWT JAN 107 CALL Dec 24 close: 4.20-4.60 Last 3.60 Vol: 0 Open interest: 2351. What does open interest mean? Any reason why this particular call has not traded over the last couple of days? -- G Regarding open interest, let me quote myself from a previous article . "Open interest reflects all transactions, spreads or otherwise. There's no distinction between a sale and purchase because both are needed to consummate a trade. Unlike stocks, which have a finite number of shares available, option open interest is unlimited. It's also a zero-sum game (also unlike stocks, where the overall value can rise or fall as the share price and market cap changes) in which the dollar amounts net out at expiration -- some people win, some lose. Here's an article in which I discuss some issues regarding open interest and what it may or may not be telling you. This past Wednesday was a holiday-shortened session, and IWM, whose options trade under the IWT symbol, only traded about 350 contracts across all strikes on the day. This was about 50% of the average daily volume. Maybe this next email will helps explain why less liquid issues can sometimes have days go by without a contract trading.