Questions about government bonds that have already matured
I am assuming that you are talking about US Savings Bonds: Here is a page that talks about maturity dates of US Savings bonds. If They aren'tSavings bonds but are another type ofUS Government Bond Assuming they are Savings bonds, here is information regarding redeeming of bonds. How do I redeem my EE/E Bonds?  Electronic bonds:     Log in to Treasury Direct and follow the directions there. The cash amount can be credited to your checking or savings account within one business day of the redemption date.  Paper bonds    You can cash paper EE/E Bonds at many local financial institutions. We don't keep a list of banks that redeem bonds, so check with banks in your area. What will I need to redeem a paper bond? Before taking in the bonds to redeem them, it's usually a good idea to check with the financial institution to find out what identification and other documents you'll need.   When you present your paper bonds, you'll be asked to show your identity. You can do this by being a customer with an active account open for at least 6 months at the financial institution that will be paying the bonds, or presenting acceptable identification such as a valid driver's license if the >redemption value of the bonds is less than $1,000. If you are not listed as the owner or co-owner on the bond, you'll have to show that you >are entitled to cash in the bond.  The treasury direct website also discusses converting bonds, rules regarding using them for education, how often they are credited with interest
Maximizing income could mean a lot of things.  What you really want is to maximize wealth.  Doesn't matter if it comes from your bond appreciating in value or as dividends. In order to maximize your wealth (that's today's wealth), you need to make decisions based on the net present value of these bonds. The market is fairly priced, especially for a tight market like government bonds.  That means if your bond falls in price, it has fallen by precisely the amount necessary so that an investor would be indifferent between purchasing it now, at its current price, and purchasing a new bond with a higher dividend.  The bonds with higher dividends will simply have a higher price, so more of the money comes as dividends than as price appreciation (at maturity it will sell for face value).  In other words, the animals are out of the barn and you have lost (or made) money already.  Changing from one bond to another will not change your wealth one way or the other. The only potential effect of changing bonds will be changing the risk of your portfolio.  If you buy a bond that matures later or has a lower dividend than your current bond, you will be adding additional interest rate risk to your portfolio.  That risk should be compensated, so you will have a higher expected return as well.  But regardless of your choice you will not be made wealthier or less wealthy by changing from one bond to another. Should you buy bonds that will earn you the most possible?  Sure, if you are below your risk tolerance.  Even among default free bonds, the longer the maturity and the lower the dividend, the greater the effect of future changes in interest rates on your bond.  That makes them riskier, but also makes them earn more money on average. TL;DR: In terms of your wealth, which is what matters, it doesn't matter whether you hold your bond or buy a new one. "According to Wikipedia, Treasury bills mature in 1 year or less to a fixed face value: Treasury bills (or T-Bills) mature in one year or less. Regular weekly T-Bills are commonly issued with maturity dates of 28 days (or 4 weeks, about a month), 91 days (or 13 weeks, about 3 months), 182 days (or 26 weeks, about 6 months), and 364 days (or 52 weeks, about 1 year). Treasury bills are sold by single-price auctions held weekly. The T-bills (as Wikipedia says, like zero-coupon bonds) are actually sold at a discount to their face value and mature to their face value. They do not return any interest before the date of maturity.  Because the amount earned is fixed at purchase, ""return"" is a more accurate term than ""rate"" when referring to a specific T-bill. The ""rate"" is the difference between this return and the discount value you purchased it at. So, yes, your rate of return is guaranteed. T-notes (1-10 year) and T-bonds (20-30 year) also have an interest rate guaranteed, but have coupon payments (usually every 6 months), paying out a fixed amount of interest on the principal.  (See more info on the same Wikipedia page.) Because those bonds are not compounding the interest it pays out, but instead paying out every 6 months, you'd have to purchase new securities to create a compound return, changing your rate of return over time slightly as the rates for new treasury securities changes." Duration is the weighted average time until all the cash flows of a fixed income security are received. There are a few different measures of duration but generally, duration measures the sensitivity of the price of a fixed income asset to a change in the yield of that asset. If you're familiar with calculus, duration is the first derivative of price with respect to yield.  Convexity is the sensitivity of the duration of bond with respect to changes in yield, or the second derivative.   The first chart [here](http://www.investopedia.com/terms/c/convexity.asp#axzz1x4F075zM) will help. Convexity measures the curvature of the blue or pink line, the steeper the curve the higher the convexity.   The more cash flows there are in a bond (higher or more frequent coupon) the lower the duration, because you are receiving more of your investment earlier as opposed to later (think time value of money). If a bond has one cash flow, meaning you get paid back only at maturity (zero coupon) then any changes in interest rates will have a greater impact on the price of the bond since you are discounting only one cash flow in the future. Think of buying a bond with no coupons and a 5% yield that matures in 5 years, or a bond with similar yield and maturity buy pays a coupon. If interest rates rise, the zero coupon bond's price will fall more than the bond with coupons. Why? Because if you own the zero coupon bond you have to wait 5 years to get your money back and reinvest it at the higher rate, while if you have the bond that pays coupons you can reinvest those incremental cash flows at the higher rate, even though at purchase they had the same yield and maturity.  These are both tough concepts that took me a fair amount of time to really understand. If you're investing in bonds or any fixed income asset, these topics are crucial to understanding interest rate risk. Since the bondholders have voted to reject the emergency manager's plan, which would have paid them pennies on the dollar, the city is now attempting to discharge its short-term and long-term debt. If they get what they want in court, it is likely these bonds will become worthless. Even if they are only able to restructure the debt, its likely that bondholders will need to accept large concessions. However, this may not be immediately reflected in bond prices as it's very possible that the market for these bonds will be very limited in terms of who they could sell them to. If you were to buy them now , that would be a bet on some outcome other than bankruptcy and the discharge of the city's long-term obligations. President Obama has already stated that he monitoring the situation, and it seems unlikely to me that after all of the support given to the auto industry in the last several years that the federal government will do nothing, if only to avert job losses. However, I think it's likely that state aid will be limited at best, as Michigan's economy has been struggling for a number of years. There aren't many large precedents to look at for guidance. One of the largest public entities to declare bankruptcy, Orange County, was a very different situation because this was due to malfeasance on the part of its investment manager, whereas Detroit's situation is a much larger structural problem with its declining economy and tax base. I think the key question will be whether the Federal Government will consider a Detroit bankruptcy to be a large enough embarassment/failure to take significant action. Why does selling a bond drive up the yield? The bond will pay back a fixed amount when it comes due. The yield is a comparison of what you pay for the bond and what will be repaid when it matures (assuming no default). Why does the yield go up if the country is economically unstable? If the country's economy is unstable, that increases the chance that they will default and not pay the full value of the bonds when they mature. People are selling them now at a loss instead of waiting for a default later for a greater loss. So if you think Greece is not going to default as it's highly likely a country would completely default, wouldn't it make sense to hold onto the bonds? Only if you also think that they will pay back the full value at maturity. It's possible that they pay some, but not all. It's also possible that they will default. It's also possible that they will get kicked out of the Euro and start printing Drachmas again, and try to pay the bonds back with those which could devalue the bonds through inflation. The market is made of lots of smart people. If they think there are reasons to worry, there probably are. That doesn't mean they can predict the future, it just means that they are pricing the risk with good information. If you are smarter than the herd, by all means, bet against them and buy the bonds now. It can indeed be lucrative if you are right, and they are wrong. The question in my view is going into Opinion and economics. Why would I buy a bond with a negative yield? I guess you have answered yourself; Although the second point is more relevant for high net worth individual or large financial institutions / Governments where preserving cash is an important consideration. Currently quite a few Govt Bonds are in negative as most Govt want to encourage spending in an effort to revive economy. "Of course it can. This is a time value of money calculation. If I knew the maturity date, or current yield to maturity I'd be able to calculate the other number and advise how much rates need to rise to cause the value to drop from 18 to 17. For a 10 year bond, a rise today of .1% will cause the bond to drop about 1% in value. This is a back of napkin calculation, finance calculators offer precision. edit - when I calculate present value with 34 years to go, and 5.832% yield to maturity, I get $14.55. At 5.932, the value drops to $14.09, a drop of 3.1%.  Edit - Geo asked me to show calculations. Here it goes - A) The simplest way to calculate present value for a zero coupon bond is to take the rate 5.832%, convert it to 1.05832 and divide into the face value, $100. I offer this as the ""four function calculator"" approach, so one enters $100 divided by 1.05832 and repeat for the number of years left. A bit of precision is lost if there's a fractional year involved, but it's close. The bid/ask will be wider than this error introduced.  B) Next - If you've never read my open declaration of love for my Texas Instruments BA-35 calculator, here it is, again. One enters N=34 (for the years) FV = 100, Rate = 5.832, and then CPT PV. It will give the result, $14.56.  C) Here is how to do it in Excel -  The numbers in lines 1-3 are self evident, the equation in cell B4 is =-PV(B3/100,B1,0,B2) - please note there are tiny differences in the way to calculate in excel vs a calculator. Excel wants the rate to be .05832, so I divided by 100 in the equation cell.  That's the best 3 ways I know to calculate present value. Geo, if you've not noticed, the time value of money is near and dear to me. It comes into play for bonds, mortgages, and many aspect of investing. The equations get more complex if there are payments each year, but both the BA-35 and excel are up to it." Savings accounts have limitations in case a bank goes belly up and you have a higher amount in the account (more than the insured amount). Mostly big corporations or pension funds cannot rely on a bank to secure their cash but a government bond is secured (with some fine print) and hence they are willing to take negative interest rates.