Share your insights or perspective on the financial matter presented in the input.

Can you beat the market by investing in double long ETFs? [duplicate]
See http://blogs.reuters.com/felix-salmon/2011/04/30/why-the-sec-should-look-at-levered-etfs/?dlvrit=60132, http://symmetricinfo.org/2011/04/are-investors-in-levered-short-treasury-etfs-a-disaster-waiting-to-happen-pt1/, and the articles linked from it: The issue with holding a levered ETF past 1 day is that investors expose themselves to path dependency in the underlying.... The reason for the difference in payouts comes from the fact that the manager of the levered ETF promises you a multiple of the daily returns of the underlying. To be able to promise you these daily returns, the ETF manager has to buy/sell some of the underlying every day to position himself to have a constant leverage ratio the next day. The short video below explains this process in detail for a 2x long ETF, but the same result holds for a 2x short ETF: the manager has to buy more of the underlying on a day when the underlying increases in value and sell more of the underlying when the underlying goes down in value .