In addition to being one of the most widely followed benchmarks in the world, the S&P 500 also serves as the basis for the world’s largest ETF. Between SPY, IVV and VOO, there is more than $160 billion linked to this index in U.S.-listed ETFs, significantly more than any other benchmark [for updates on all new ETFs, sign up for the free ETFdb newsletter]. Most investors know that the S&P 500 includes exposure to the largest U.S.-listed companies, giving the biggest weights to the most valuable companies. But that’s not entirely the case; the cap-weighted methodology used by S&P makes an adjustment for the “free float” outstanding. In other words, it excludes shares deemed to be locked in–held by the government, restricted insiders or otherwise unable to be publicly acquired–from its calculation [see 5 Important ETF Lessons In Pictures]. In many cases, that hardly puts a dent in the value [...] Click here to read the original article on ETFdb.com. Related Posts: Are UITs Better Than ETFs? Breaking Down The S&P 500 ETF Price War VelocityShares Fills Pipeline First Trust Debuts “Tail Hedge” S&P 500 ETF (VIXH) ETF Pop Quiz: Emerging Markets, Junk Bonds, And Spain