A file extension is the characters after the last dot in a file name. For example, in the file name winmail.dat, the file extension is dat. It helps Windows select the right program to open the file.
Margin is borrowing money from your broker to buy a stock and using your investment as collateral. Investors generally use margin to increase their purchasing power so that they can own more stock without fully paying for it.But margin exposes investors to the potential for higher losses.ut if you bought the stock on margin  paying $25 in cash and borrowing $25 from your broker  you'll earn a 100 percent return on the money you invested. Of course, you'll still owe your firm $25 plus interest.
About Market Capitalization. Market Capitalization (Market Cap) is a measurement of business value based on share price and number of shares outstanding. It generally represents the market's view of a company's stock value and is a determining factor in stock valuation. For example, if a company has 1.5 million shares outstanding at a share price of $25, its market cap is $37.5 million (1.5 million x $25). Companies can be categorized based upon the size of their market capitalization. There are five basic groups: mega-cap (market cap over $200B), large-cap ($10Bâ$200B), mid-cap ($2Bâ$10B), small-cap ($300Mâ$2B), and micro-cap ($50M-$300M).