IWR delivers the US mid-cap market well via a large and representative basket of stocks. The fund ventures a little deeper into the large-cap space, so its top 10 holdings differ from those of our index. This large-cap bias shows up in slightly lower market risk to our midcap benchmark. The size tilt also plays out in subtle sector biases. IWR is one of the best choices for retail investors and frequent traders alike. It's easy to deal in IWR at any scale. The fund tracks well and even earns some of its fees back via securities lending.