Exchange-traded funds (ETFs) and "Buffettology" provide investors with the opportunity to pair one of the most popular investment vehicles with the investing approach of one of the most successful investors. One popular investing strategy is to emulate a successful investor, such as Warren Buffett, the famed "Oracle of Omaha." Buffett is probably most accurately described as a long-term value investor. He does not look so much for stocks selling at a bargain basement price as he does for reasonably priced stocks of companies he believes will continue to be financially solid with long-term growth potential. Also, while Buffett has invested in a variety of sectors over the years, companies within the financial sector, such as Wells Fargo & Company and GEICO, remain prominent among Berkshire Hathaway investments.

Some investors have sought to follow Buffett by purchasing Berkshire Hathaway stock or by purchasing the stocks of individual companies owned or invested in by Berkshire Hathaway. However, as ETFs have become a favored investment vehicle, some investors are looking to use them as a way to follow Buffett's investing principles. There is no specific Warren Buffett ETF, but there are some that aim to make Buffett-like investments, including the three described below.

Market Vectors Wide Moat ETF

The term "moat" as it relates to investing was coined by Buffett to describe any company with a competitive advantage within an industry that offers it moat-like protection. The Market Vectors Wide Moat ETF (NYSEARCA: MOAT), launched by Van Eck Global in 2012, aims to identify and invest in such companies. The fund seeks to employ its $774 million in assets in tracking the performance of the Morningstar Wide Moat Focus Index. The underlying index offers investors exposure to the 20 most attractively priced companies that Morningstar's equity research team identified as having sustainable competitive advantages within their respective industries. This medium-risk-rated fund has an expense ratio of 0.49% and offers a dividend yield of 1.41%. The three-year annualized return as of 2015 is 10.08%. Major portfolio holdings include News Corporation, the Procter & Gamble Company, Union Pacific Corporation, Time Warner and Berkshire Hathaway.

SPDR Financial Select Sector ETF

The SPDR Financial Select Sector ETF (NYSEARCA: XLF) offers broad exposure to companies in the financial sector, and it also invests directly in Berkshire Hathaway stock, which accounts for nearly 9% of the fund's portfolio holdings. This fund was launched by State Street Global Advisors in 1998. It tracks the performance of the S&PFinancial Select Sector Index, which includes companies from the broad financial services sector including banks, insurance companies, thrifts and REITs. The fund's expense ratio is a low 0.15%, and it offers a dividend yield of 1.87%. In addition to Berkshire Hathaway, the fund's major holdings include Wells Fargo, JPMorgan Chase, Goldman Sachs and American Express. Although given an above-average risk rating by Morningstar, the fund's five-year annualized return as of 2015 is 11.43%.

iShares MSCI USA Quality Factor ETF

The iShares MSCI USA Quality Factor ETF (NYSEARCA: QUAL), launched in 2013 by BlackRock, has over $1.4 billion in assets. The fund aims to invest in high-quality stocks by tracking the MSCI USA Sector Neutral Quality Index, which invests in large- and mid-cap stocks selected on the basis of three fundamental metrics: debt to equity (D/E), return on equity (ROE) and earnings variability. The fund's total return since its inception is 10.57%. It has an expense ratio of 0.15% and a dividend yield of 1.59%. This medium-risk-rated fund is heavily invested in the technology, financial and health care sectors. Major portfolio holdings include Apple, Johnson & Johnson, Gilead Sciences, Berkshire Hathaway and MasterCard.