Gallery. 1  Hand-cranked planetary sharpener, with cover in place. 2  Hand-cranked planetary sharpener from 1950â60, with cover removed. 3  Hand-cranked planetary sharpener with spring-driven pencil holder. 4  AC-powered electric pencil sharpener. 5  Battery-operated sharpener.
Description. Tracking Error is a measure of how closely an ETF follows its benchmark index. This data point seeks to isolate the ability of the portfolio managers to track the index, ignoring the confounding effects of ETF liquidity on market prices.escription. Tracking Error is a measure of how closely an ETF follows its benchmark index. This data point seeks to isolate the ability of the portfolio managers to track the index, ignoring the confounding effects of ETF liquidity on market prices.
DEFINITION of 'Exchange-Traded Fund (ETF)'. An ETF, or exchange traded fund, is a marketable security that tracks an index, a commodity, bonds, or a basket of assets like an index fund. Unlike mutual funds, an ETF trades like a common stock on a stock exchange. ETFs experience price changes throughout the day as they are bought and sold.