The WisdomTree U.S. MidCap Dividend ETF (DON) made its debut on 06/16/2006, and is a smart beta exchange traded fund that provides broad exposure to the Style Box - Mid Cap Value category of the market.What Are Smart Beta ETFs?Products that are based on market cap weighted indexes, which are strategies designed to reflect a specific market segment or the market as a whole, have traditionally dominated the ETF industry.A good option for investors who believe in market efficiency, market cap weighted indexes offer a low-cost, convenient, and transparent way of replicating market returns.There are some investors, though, who think it's possible to beat the market with great stock selection; this group likely invests in another class of funds known as smart beta, which track non-cap weighted strategies.Based on specific fundamental characteristics, or a combination of such, these indexes attempt to pick stocks that have a better chance of risk-return performance.Methodologies like equal-weighting, one of the simplest options out there, fundamental weighting, and volatility/momentum based weighting are all choices offered to investors in this space, but not all of them can deliver superior returns.Fund Sponsor & IndexManaged by Wisdomtree, DON has amassed assets over $2.82 billion, making it one of the larger ETFs in the Style Box - Mid Cap Value. Before fees and expenses, this particular fund seeks to match the performance of the WisdomTree U.S. MidCap Dividend Index.The WisdomTree U.S. MidCap Dividend Index is a fundamentally weighted index that measures the performance of the mid-capitalization segment of the US dividend-paying market.Cost & Other ExpensesSince cheaper funds tend to produce better results than more expensive funds, assuming all other factors remain equal, it is important for investors to pay attention to an ETF's expense ratio.With on par with most peer products in the space, this ETF has annual operating expenses of 0.38%.DON's 12-month trailing dividend yield is 2.81%.Sector Exposure and Top HoldingsIt is important to delve into an ETF's holdings before investing despite the many upsides to these kinds of funds like diversified exposure, which minimizes single stock risk. And, most ETFs are very transparent products that disclose their holdings on a daily basis.DON's heaviest allocation is in the Financials sector, which is about 23.80% of the portfolio. Its Industrials and Utilities round out the top three.When you look at individual holdings, Evergy Inc (EVRG) accounts for about 1.51% of the fund's total assets, followed by Cardinal Health Inc (CAH) and Continental Resources Inc/ok (CLR).The top 10 holdings account for about 10.89% of total assets under management.Performance and RiskYear-to-date, the WisdomTree U.S. MidCap Dividend ETF has lost about -13.68% so far, and is down about -8.74% over the last 12 months (as of 09/28/2022). DON has traded between $37.71 and $45.36 in this past 52-week period.DON has a beta of 1.05 and standard deviation of 29.02% for the trailing three-year period, which makes the fund a medium risk choice in the space. With about 337 holdings, it effectively diversifies company-specific risk.AlternativesWisdomTree U.S. MidCap Dividend ETF is an excellent option for investors seeking to outperform the Style Box - Mid Cap Value segment of the market. There are other ETFs in the space which investors could consider as well.IShares Russell MidCap Value ETF (IWS) tracks Russell MidCap Value Index and the Vanguard MidCap Value ETF (VOE) tracks CRSP U.S. Mid Cap Value Index. IShares Russell MidCap Value ETF has $11.84 billion in assets, Vanguard MidCap Value ETF has $14.20 billion. IWS has an expense ratio of 0.23% and VOE charges 0.07%.Investors looking for cheaper and lower-risk options should consider traditional market cap weighted ETFs that aim to match the returns of the Style Box - Mid Cap Value.Bottom LineTo learn more about this product and other ETFs, screen for products that match your investment objectives and read articles on latest developments in the ETF investing universe, please visit Zacks ETF Center. Want key ETF info delivered straight to your inbox? Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week.Get it free >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report WisdomTree U.S. MidCap Dividend ETF (DON): ETF Research Reports Cardinal Health, Inc. (CAH): Free Stock Analysis Report Continental Resources, Inc. (CLR): Free Stock Analysis Report Vanguard MidCap Value ETF (VOE): ETF Research Reports iShares Russell MidCap Value ETF (IWS): ETF Research Reports Evergy Inc. (EVRG): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research