In the first essay, we evaluate the performance of commodity mutual funds. The use of commodities to hedge inflation risk and diversify portfolios is generally considered to be an important consideration for portfolio management. Direct investment in commodities or commodity derivatives requires that investors have significant assets and/or expertise in these commodities or their respective derivatives markets. As an alternative to direct investment, investors in recent years have increasingly resorted to the use of commodity based mutual funds. At issue is the question of whether or not these funds are delivering the benefits investors expect. In this paper we evaluate the performance, persistence, market timing and selectivity of four categories of mutual funds whose returns are based on commodity prices over the time period from each fund's inception through December, 2012. Our results indicate that these funds have not been able to create positive alphas for their investors; have negative or insignificant performance persistence; and have no market timing ability. Some of the categories of funds, however do exhibit some selectivity. We did find that when these commodity based funds' performance was evaluated during specific time periods of market downturns (e.g., the 2000 stock market downturn and the 2007 financial crisis), their performance was significantly positive which indicates that these funds provide a good hedge during bear markets/financial crises. The second essay evaluates the performance and diversification benefits of international ETFs for U.S. investors during and after the recent financial crisis. Our results show that U.S. ETFs outperform all categories of international ETFs for the period of our study (January 2008 - June 2013); they have higher average monthly returns, lower risk (standard deviation of returns), higher risk-adjusted performance (Sharpe, Sortino, and Treynor ratios) and the highest cumulative returns over the entire period. When we form equally weighted portfolios of each ETF category and compute their risk-adjusted performance, we again find that U.S. ETF portfolios had the best performance for the entire period. We also find that U.S. ETFs have the lowest tracking error during the entire period. Most of these ETFs passively track the benchmark and do not manage for positive alpha. Previous research has questioned the diversification benefits of international investing during times of financial distress. We find that international ETFs are highly dependent on major U.S. indices, therefore, they offer limited diversification benefits for U.S. investors. "In business, I look for economic castles protected by unbreachable 'moats'." Warren Buffett The third essay evaluates the performance of Wide Moat stocks. Companies that have sustainable competitive advantages should be able to create a barrier (moat) to prevent or lessen competition from other firms. The wider the moat the greater the barrier and the more secure the company's profitability. Using the Morningstar classification of "Wide Moat" stocks, we construct annually rebalanced equal- and value-weighted portfolios to analyze their performance in order to determine if they deliver superior performance relative to standard benchmark portfolios. The period for our analysis extends from June 2002 through May 2014. We find that the "Wide Moat" portfolios outperform both the S & P 500 and Russell 3000 indices generating higher average monthly and annualized returns, Sharpe Ratio, Sortino Ratio, Treynor Ratio, Omega Ratio, Upside Potential Ratio, M2, M2 Alpha and cumulative returns. When we compute alpha using Carhart four-factor and Fama-French five-factor models, we find that "Wide Moat" portfolios had significantly positive risk-adjusted alphas with both the models. "Wide Moat" portfolios also lost less value during the 2007-2009 financial crisis compared to both S & P 500 and Russell 3000. In conclusion, we find that "Wide Moat" stocks have created significant value for their investors over the course of our study.