fA bond is a promise (typically by a business or a government) to pay a predetermined amount and schedule of interest payments. The interest rate on the bond is called the coupon, the amount borrowed is the face value, and the date on which the issuer has to repay the face value is the maturity date. The face value is the amount of money a holder will get back once a bond matures. Bonds are sold at lower than the face, or par value. When a bond trades at a price above the face value, it is selling at a premium. When it is selling below face value, it is selling at a discount. The chance that the company might not be able to pay the par value of the bond is known as default risk, and this risk means corporate bonds are offered at a higher yield in order to entice investors. Various bond rating systems help investors determine a company's creditworthiness. Bonds are publicly traded securities, which means not every lender holds them until maturity. At any time, a bond can be sold on the open market, where the price may fluctuate. Yield shows the price you get on a bond. Simply put, yield equals the coupon amount divided by price. In the real world of market variation, bond investors refer to yield as yield to maturity (YTM). YTM equals all the interest payments the buyer will receive plus any gain or loss. Simply put, when price increases, yield decreases. Government bonds can be divided into bills (maturing in less than one year), notes (maturing in one to 10 years), and bonds (maturing in more than 10 years). Municipal bonds are issued by municipalities and are attractive to investors seeking a tax-free investment. Corporate bonds are issued by companies and are characterized by higher yields because of the relatively higher risk of a company defaulting. Variations on corporate bonds include convertible bonds and callable bonds. Zero-coupon bonds make no coupon payments but instead are issued at a considerable discount to par value. 「債券」(通常由一個企業或政府所提供)是一種願意支付預定金額和按時撥付利息的承諾。 債券的利率稱為「票息」，借入的金額是「票面價值」，而發行人償還票面價值的日期則為「到期日」。 「票面價值」是持有人在債券到期時取得的金額。債券通常以低於面額的價格出售。當債券以高於面額的價格交易，則為溢價出售，低於面額則為折價。 公司可能無法支付債券面額的風險，稱為「違約風險」。這種風險是指為了吸引投資人，公司債券以較高的殖利率發行。而各種的債券評等系統，能夠幫助投資人判斷公司的信用度。 債券是公開交易的證券，表示不是每個貸款人都會持有債券至到期日。在任何時候，債券都可在公開市場上賣出，價格也可能出現波動。「殖利率」代表你從債券獲得的投資報酬率，簡單的說，「殖利率」等於債券的票息除以價格。現實世界的市場不斷變動，因此債券投資人所提的殖利率為「到期殖利率」(YTM)。YTM等於買方收取的所有利息支付金額，加上任何獲利或虧損。簡言之，當價格上漲時，殖利率就下跌。 政府債券可分為「短期債券」(一年內到期)，「中期債券」(1年至10年到期)和「長期債券」(10 年以上到期)。地方政府債券由市政府發行，吸引尋求免稅投資的投資人。公司債券則由企業發行，殖利率更高，因為企業違約的風險相對較高。公司債券的其他種類還包括「可轉換公司債」和「可贖回債券」。「零息債券」不支付票息，而是以低於票面價值的大幅折價發行。 | 
