What bonds do I keep and which do I cash, why is the interest so different
Bonds released at the same time have different interest rates because they have different levels of risks and liquidity associated.  Risk will depend on the company / country / municipality that offers the bond: their financial position, and their resulting ability to make future payments & avoid default. Riskier organizations must offer higher interest rates to ensure that investors remain willing to loan them money. Liquidity depends on the terms of the loan - principal-only bonds give you minimal liquidity, as there are no ongoing interest payments, and nothing received until the bond's maturity date. All bonds provide lower liquidity if they have longer maturity dates. Bonds with lower liquidity must have higher returns to compensate for the fact that you will have to give up your cash for a longer period of time. Bonds released at different times will have different interest rates because of what the general 'market rate' for interest was in those periods. ie: if a bond is released in 2016 with interest rates approaching 0%, even a high risk bond would have a lower interest rate than a bond released in the 1980s, when market rates were approaching 20%. Some bonds offer variable interest tied to some market indicator - those will typically have higher interest at the time of issuance, because the bondholder bears some risk that the prevailing market rate will drop. Note regarding sale of bonds after market rates have changed: The value of your bonds will fluctuate with the market. If a bond was offered with 1% interest, and next year interest rates go up and a new identical bond is offered for 2% interest, when you sell your old bond you will take a loss, because the market won't want to pay full price for it anymore. Whether you should sell lower-interest rate bonds depends on how you feel about the factors above - do you want junk bonds that have stock-like levels of returns but high risks of default, maturing in 30 years? Or do you want AAA+ Bonds that have essentially 0% returns maturing in 30 days? If you are paying interest on debt, it is quite likely that you could achieve a net income benefit by selling the bonds, and paying off debt [assuming your debt has a higher interest rate than your low-rate bonds]. Paying off debt is sometimes referred to as a 'zero risk return', because essentially there is no real risk that your lender would otherwise go bankrupt. That is, you will owe your bank the car loan until you pay it, and paying it is the only thing you can do to reduce it.  However, some schools of thought suggest that maintaining savings + liquid investments makes sense even if you have some debt, because cash + liquid investments can cover you in some emergencies that credit cards can't help you with. ie: if you lose your job, perhaps your credit could be pulled and you would have nothing except for your liquid savings to tide you over. How much you should save in this way is a matter of opinion, but often repeated numbers are either 3 months or 6 months worth [which is sometimes taken as x months of expenses, and sometimes as x months of after-tax income]. You should look into this issue further; there are many questions on this site that discuss it, I'm sure.
"The answer to almost all questions of this type is to draw a diagram.  This will show you in graphical fashion the timing of all payments out and payments received.  Then, if all these payments are brought to the same date and set equal to each other (using the desired rate of return), the equation to be solved is generated. In this case, taking the start of the bond's life as the point of reference, the various amounts are: Pay out = X Received = a series of 15 annual payments of $70, the first coming in 1 year.  This can be brought to the reference date using the formula for the present value of an ordinary annuity. PLUS Received = A single payment of $1000, made 15 years in the future.  This can be brought to the reference date using the simple interest formula. Set the pay-out equal to the present value of the payments received and solve for X I am unaware of the difference, if any, between ""current rate"" and ""rate to maturity"" Finding the rate for such a series of payments would start out the same as above, but solving the resulting equation for the interest rate would be a daunting task..." Yes, the interest rate on a Treasury does change as market rates change, through changes in the price. But once you purchase the instrument, the rate you get is locked in. The cashflows on a treasury are fixed. So if the market rate increase, the present value of those future cashflows decreases, so the price of the treasury decreases. If you buy the bond after this happens, you would pay a lower price for the same fixed cashflows, hence you will receive a higher rate. Note that once you purchase the treasury instrument, your returns are locked in and guaranteed, as others have mentioned. Also note that you should distinguish between Treasury Bills and Treasury Bonds, which you seem to use interchangeably. Straight from the horse's mouth, http://www.treasurydirect.gov/indiv/products/products.htm: Treasury Bills are short term securities with maturity up to a year, Treasury Notes are medium term securities with maturity between 1 and 10 years, and Treasury Bonds are anything over 10 years. Bonds can increase in price, if the demand is high and offer solid yield if the demand is low.  For instance, Russian bond prices a year ago contracted big in price (ie: fell), but were paying 18% and made a solid buy.  Now that the demand has risen, the price is up with the yield for those early investors the same, though newer investors are receiving less yield (about 9ish percent) and paying higher prices.   I've rarely seen banks pay more variable interest than short term treasuries and the same holds true for long term CDs and long term treasuries.  This isn't to say it's impossible, just rare.  Also variable is different than a set term; if you buy a 10 year treasury at 18%, that means you get 18% for 10 years, even if interest rates fall four years later.   Think about the people buying 30 year US treasuries during 1980-1985.  Yowza. So if you have a very large amount of money you will store it in bonds as its much less likely that the US treasury will go bankrupt than your bank. Less likely?  I don't know about your bank, but my bank doesn't owe $19 trillion. "You are asking multiple questions here, pieces of which may have been addressed in other questions.  A bond (I'm using US Government bonds in this example, and making the 'zero risk of default' assumption) will be priced based on today's interest rate. This is true whether it's a 10% bond with 10 years left (say rates were 10% on the 30 yr bond 20 years ago) a 2% bond with 10 years, or a new 3% 10 year bond.  The rate I use above is the 'coupon' rate, i.e. the amount the bond will pay each year in interest. What's the same for each bond is called the ""Yield to Maturity."" The price adjusts, by the market, so the return over the next ten years is the same.  A bond fund simply contains a mix of bonds, but in aggregate, has a yield as well as a duration, the time-and-interest-weighted maturity.  When rates rise, the bond fund will drop in value based on this factor (duration). Does this begin to answer your question?" I see three ways to do this. Note that I kept saying interest. I assumed for this answer you were only considering money being saved in a savings account. Money that is to be invested for the long term (college fund, retirement) have much different rules for contributions, use, deductibility, age rules: that they would tend not to be mixed within the same account. You only pay tax on the capital gain of the bond, not the principal, unless the source of the money for the principal was gain from another investment, if that makes sense.   In other words, if you bought the bond with income earned from your job, that money was already taxed as income, so it isn't subject to taxation again when you redeem the bond.  On the other hand, if you cashed out of one investment and used those proceeds to buy a bond, then the entire amount might be taxable. The key word is 'After-Tax' money - you started with after-tax money, so you already paid taxes on it. Everything else is just moving it from freely available into ROTH, which locks it away a bit, but makes the interest tax-free. "You get paid interest on deposits because banks only keep a fraction of the deposits on-hand. The rest is put to other uses, such as loaning money to others. If you deposit money and yield 1% interest, the bank is able to fund an auto loan, at 5%. By saving, you are actually making more capital available in the marketplace. ""Fixed"" or ""durable"" assets like gold, real property, or durable goods are different -- their value is based on attributes such as demand (gold, oil) or location (real property). If you bought an apartment in Manhattan in 1975, it appreciated greatly in value over the course of 30 years... but it did so because demand for apartments in New York City grew, while the supply of apartments grew more slowly. The government prints money for two core reasons: Think of it this way: Money is valuable because it is money." If the market rate and coupon were equal, the bond would be valued at face value, by definition. (Not 100% true, but this is an exercise, and that would be tangent to this discussion).  Since the market rate is higher than the coupon rate, the value I am willing to pay drops a bit, so my return is the same as the market rate.  This can be done by hand, a time value of money calculation for each payment. Discount by the years till received at the market rate to get the present value for each payment, and sum up the numbers.  The other way is to use a finance calculator and solve for rate.  The final payment of $10,000 (ignore final coupon just now) is $10,000/(1.1^5). In other words, that single chunk of cash is worth 10% less if it's one year away, (1.1)^2 if 2 years away, etc.  Draw a timetable with each payment and divide by 1.1 for each year it's away from present. If the 9% coupon is really 4.5% twice a year, it's $450 in 6 month intervals, and each 6 mo interval is really 5% you discount.  Short durations like this can be done by hand, a 30 year bond with twice a year payments is a pain.  Welcome to Money.SE. If I invest X each month, where does X go - an existing (low yield)   bond, or a new bond (at the current interest rate)? This has to be viewed in a larger context.  If the fund has outflows greater than or equal to inflows then chances are there isn't any buying being done with your money as that cash is going to those selling their shares in the fund.  If though inflows are greater than outflows, there may be some new purchases or not.  Don't forget that the new purchase could be an existing bond as the fund has to maintain the duration of being a short-term, intermediate-term or long-term bond fund though there are some exceptions like convertibles or high yield where duration isn't likely a factor. Does that just depend on what the fund manager is doing at the time   (buying/selling)? No, it depends on the shares being created or redeemed as well as the manager's discretion. If I put Y into a fund, and leave it there for 50 years, where does Y   go when all of the bonds at the time I made the purchase mature?  You're missing that the fund may buy and sell bonds at various times as for example a long-term bond fund may not have issues nearing maturity because of what part of the yield curve it is to mimic. Does Y just get reinvested in new bonds at the interest rate at that time? Y gets mixed with the other money in the fund that may increase or decrease in value over time.  This is part of the risk in a bond fund where NAV can fluctuate versus a money market mutual fund where the NAV is somewhat fixed at $1/share. Okay let's try this a different way. Completely forget about what the bond is with. Here is how a bond works:   * You get paid interest for holding the bond (5% interest means a coupon of $50 assuming one coupon a year)    * At the end of the bond term (maturity) you get paid $1000.     In your scenario, you get paid the $50 as an interest payment and the $1000 final payment.    If you only had the bond for one year, your total payment will be $1050.     Try drawing a timeline to visualise it a bit better "Hey guys I have a quick question about a financial accounting problem although I think it's not really an ""accounting"" problem but just a bond problem.  Here it goes    GSB Corporation issued semiannual coupon bonds with a face value of $110,000 several years ago. The annual coupon rate is 8%, with two coupons due each year, six months apart. The historical market interest rate was 10% compounded semiannually when GSB Corporation issued the bonds, equal to an effective interest rate of 10.25% [= (1.05 × 1.05) – 1]. GSB Corporation accounts for these bonds using amortized cost measurement based on the historical market interest rate. The current market interest rate at the beginning of the current year on these bonds was 6% compounded semiannually, for an effective interest rate of 6.09% [= (1.03 × 1.03) – 1]. The market interest rate remained at this level throughout the current year. The bonds had a book value of $100,000 at the beginning of the current year. When the firm made the payment at the end of the first six months of the current year, the accountant debited a liability for the exact amount of cash paid. Compute the amount of interest expense on these bonds for the last six months of the life of the bonds, assuming all bonds remain outstanding until the retirement date.  My question is why would they give me the effective interest rate for both the historical and current rate?  The problem states that the firm accounts for the bond using historical interest which is 10% semiannual and the coupon payments are 4400 twice per year.  I was just wondering if I should just do the (Beginning Balance (which is 100000 in this case) x 1.05)-4400=Ending Balance so on and so forth until I get to the 110000 maturity value. I got an answer of 5474.97 and was wondering if that's the correct approach or not." The 10yr bond pays coupons semi annually.  The yield % is what you would get annually if you hold the bond to full term.  The coupon payment won't be exactly 1.65%/2 because of how bond pricing and yields work.  The yield commonly quoted does not tell you how much each interest payment is.  You have to look at the price and coupon of a specific individual bond.  The rate you see is the market equilibrium yield at the present.      Example, I offer two different people two different bonds.  Joe buys a 10yr bond paying 5% coupons semi annually at a par value of $1000.  I charge him $1000.  Bob wants to buy a 10yr bond paying 10% coupons semi annually at a par value of $1000.  I charge him $1500 for this.   The yield is similar between the two (not equal due to math details but lets assume).  So at the end of 10 yrs, the two have roughly the same total amount of $.  Bob's paid more each year but he paid more up front.    This is why the federal govt can issue bonds with diff coupons and the market prices them so the yield rises/falls to the market clearing yield. Different stakeholders receive cash flows at different times. The easiest way for me to remember is if you're a debt holder vs equity owner on an income statement. Interest payments are made before net income, so debt holders are repaid before any residual cash flows go to equity owners. Imagine that the existing interest rate is 5%. So on a bond with face value of 100, you would be getting a $5 coupon implying a 5% yield. Now, if let's say the interest rates go up to 10%, then a new bond issued with a face value of 100 will give you a coupon of $10 implying a 10% yield. If someone in the bond market buys your bond after interest price adjustment, in order to make the 10% yield (which means that an investor typically targets at least the risk-free rate on his investments) he needs to buy your bond at $50 so that a $5 coupon can give a 10% yield. The reverse happens when interest rates go down. I hope this somewhat clears the picture. Yield = Coupon/Investment Amount Update: Since the interest rate of the bond does not change after its issuance, the arbitrage in the interest rate is reflected in the market price of the bond. This helps in bringing back the yields of old bonds in-line with the freshly issued bonds.