Current Coupon
  
You want to buy a bond. Let’s say you’re willing to buy a bond from someone who has already started to offer payments. If that bond is paying the same yield and trades at par with its original value and terms, you have what is known as a current coupon.
Interest rates can swing up and down for a variety of reasons. The Fed might push them higher to combat inflation, or concerns about a nation’s currency may press them higher. Strong economic growth might beget lower rates.
That said, bond prices do fluctuate based on macroeconomic issues, or micro issues that impact a company’s bottom line and credit rating.