As with other earnings-related plays, conservative ETF investors who do not already own shares of the funds listed above would be best off waiting on the sidelines until after Apple releases its statement. Knee-jerk reactions can be steep, especially for a company as closely watched as Apple. Investors learned this the hard way last quarter. Following the firm's miss, shares dove 6% in after-hours trading. Thanks to their top-heaviness, any fluctuation from Apple will noticeably impact the performance of QQQ, XLK, and IYW. It is easy to get caught up in the excitement surrounding a company as popular as Apple. However, when it comes to constructing a strong, long-term portfolio, investors must make an effort to avoid letting their emotions drive their investing decisions. Let initial reactions cool before testing these waters. Written by Don Dion in Williamstown, Mass.