Burton Malkiel and Jack Bogle are both strong proponents of indexing, but they have widely divergent views of exchange-traded funds, or ETFs—trackers that are priced intraday and can be traded just like shares. Malkiel, who set forth the folly of trying to beat the market in his book, “A Random Walk Down Wall Street,” believes ETFs provide a low-cost, tax-efficient method of investing in the market, and that they give short-term traders a vehicle to trade where they can’t damage the interests of long-term investors. Whilst Bogle recognises some of the benefits of ETFs, he believes they give investors another way to harm themselves by encouraging short-trading—a practice at which many investors can quickly lose money. The firm Bogle founded, US indexing giant Vanguard, added a lineup of ETFs to its offerings after Jack Brennan replaced Bogle as CEO.