Lend money at a rate linked to the prime rate
Yes.  In the US these are called certificates of deposit or savings accounts.  Every run-of-the-mill bank offers them.  You give the bank money and in return they pay you an interest rate that is some fraction of or (negative) offset from the returns they expect to make from your money. Since most investments that a bank makes (say, loaning money to a local business) are themselves based on some multiple of or (positive) offset from the prime rate, in return the interest rate that they offer you is also mathematically based on the prime rate. You can find lists of banks offering the best returns on CDs or savings accounts at sites like BankRate.
What you are looking here is the cost of capital, because that is what you are effectively giving up in order to invest in those loans. In a discounted cash-flow, it would be the *i* in the denominator (1+*i*). For instance, instead of purchasing those loans you could have lent your money at the risk-free rate (not 100% true, but typical assumption), and therefore you are taking a slight risk in those loans for a higher return.  There are several ways to compute that number, the one most often used would be the rate if the bank were to lend that money. In this way, it would be the Fed Funds rate plus some additional risk premium. I got that notion from Max Kaiser, his ideas about that are mostly about interest rate apartheid - banks and rich people get money at zero interest, we pay 9, 10, 30%.  I think it involves everything from how we are seen in the eyes of the law to assuming risk, etc.  We are expected to play by the rules and they are not. Basically, what you describe exists in many countries - not in the USA though. In Europe, people have checking accounts with allowed overdraft, typically three month net salaries. You can just this money any day as you like, and pay it back - completely or partially - any day as you like. Interest is calculated for each day on the amount used that day; and the collateral is 'future income', predicted / expected from previous income. In the USA, credit cards have taken its place, with stricter different rules and limitations. In addition, many of the extra rules in loans were invented to take advantage of the ignorance or situation of the borrower to make even more money. For example, applying extra payments to future due payments instead of to the principal makes that principal produce more interest while the extra payments just sit around. It's easiest to get your payment from the PMT function in Excel or Google Sheets.  So a $100,000 30 year mortgage at 3% looks like this: The basic calculation is pretty simple.  You take the annual interest rate, say 3%, divided by 12, times the existing principal balance: The idea is that borrowers would like to have a predictable payment.  The earlier payments are proportionally more interest than principal than later payments are but that's because there is much more principal outstanding on month 1 than on month 200. "This is the best tl;dr I could make, [original](https://www.nytimes.com/2017/07/27/business/dealbook/libor-fca-banks-andrew-bailey.html) reduced by 82%. (I'm a bot) ***** &gt; The one-year Libor, which represents the rate of interest on a loan between banks to be paid back within a year, is the most commonly used index for mortgages in the United States, according to the Consumer Financial Protection Bureau.  &gt; &amp;quot;And while we have given our full support to encouraging panel banks to continue to contribute and maintaining Libor over recent years, we do not think markets can rely on Libor continuing to be available indefinitely.""  &gt; Mr. Bailey said that the regulator had agreed with the panel banks to sustain Libor through 2021 to smooth a transition to new rates.   ***** [**Extended Summary**](http://np.reddit.com/r/autotldr/comments/6r14fz/libor_brought_scandal_greatest_financial_scandal/) | [FAQ](http://np.reddit.com/r/autotldr/comments/31b9fm/faq_autotldr_bot/ ""Version 1.65, ~180937 tl;drs so far."") | [Feedback](http://np.reddit.com/message/compose?to=%23autotldr ""PM's and comments are monitored, constructive feedback is welcome."") | *Top* *keywords*: **Libor**^#1 **rate**^#2 **bank**^#3 **over**^#4 **Financial**^#5" Generally, if you watch for the detail in the fine print, and stay away from non-FDIC insured investments, there is little difference, so yes, pick the highest you can get. The offered interest rate is influenced by what the banks are trying to accomplish, and how their current and desired customer base thinks. Some banks have customer bases with very conservative behavior, which will stick with them because they trust them no matter what, so a low interest rate is good enough. The disadvantage for the bank is that such customers prefer brick-and-mortar contact, which is expensive for the bank. Or maybe the bank has already more cash than they need, and has no good way to invest it. Other banks might need more cash flow to be able to get stronger in the mortgage market, and their way of getting that is to offer higher interest rates, so new customers come and invest new money (which the bank in turn can then mortgage out). They also may offer higher rates for online handling only. Overall, there are many different ways to make money as a bank, and they diversify into different niches with other focuses, and that comes with offering quite different interest rates. This is of course using 'new math'.  Namely, if I lend you $100 and you keep it for a month, I've lent you $100.  In fact, if I loan you $100 for a year I've loaned you $100.  But if I lend you $100 overnight, you pay me back in the morning, I lend you $100 overnight, you pay me back in the morning and we repeat that for a month, I've supposedly lent you $3,000.    That's some interesting math for sure. "My answer is specific to the US because you mentioned the Federal Reserve, but a similar system is in place in most countries. Do interest rates increase based on what the market is doing, or do they solely increase based on what the Federal Reserve sets them at? There are actually two rates in question here; the Wikipedia article on the federal funds rate has a nice description that I'll summarize here. The interest rate that's usually referred to is the federal funds rate, and it's the rate at which banks can lend money to each other through the Federal Reserve. The nominal federal funds rate - this is a target set by the Board of Governors of the Federal Reserve at each meeting of the Federal Open Market Committee (FOMC). When you hear in the media that the Fed is changing interest rates, this is almost always what they're referring to. The actual federal funds rate - through the trading desk of the New York Federal Reserve, the FOMC conducts open market operations to enforce the federal funds rate, thus leading to the actual rate, which is the rate determined by market forces as a result of the Fed's operations. Open market operations involve buying and selling short-term securities in order to influence the rate. As an example, the current nominal federal funds rate is 0% (in economic parlance, this is known as the Zero Lower Bound (ZLB)), while the actual rate is approximately 25 basis points, or 0.25%. Why is it assumed that interest rates are going to increase when the Federal Reserve ends QE3? I don't understand why interest rates are going to increase. In the United States, quantitative easing is actually a little different from the usual open market operations the Fed conducts. Open market operations usually involve the buying and selling of short-term Treasury securities; in QE, however (especially the latest and ongoing round, QE3), the Fed has been purchasing longer-term Treasury securities and mortgage-backed securities (MBS). By purchasing MBS, the Fed is trying to reduce the overall risk of the commercial housing debt market. Furthermore, the demand created by these purchases drives up prices on the debt, which drives down interest rates in the commercial housing market. To clarify: the debt market I'm referring to is the market for mortgage-backed securities and other debt derivatives (CDO's, for instance). I'll use MBS as an example. The actual mortgages are sold to companies that securitize them by pooling them and issuing securities based on the value of the pool. This process may happen numerous times, since derivatives can be created based on the value of the MBS themselves, which in turn are based on housing debt. In other words, MBS aren't exactly the same thing as housing debt, but they're based on housing debt. It's these packaged securities the Fed is purchasing, not the mortgages themselves.  Once the Fed draws down QE3, however, this demand will probably decrease. As the Fed unloads its balance sheet over several years, and demand decreases throughout the market, prices will fall and interest rates in the commercial housing market will fall. Ideally, the Fed will wait until the economy is healthy enough to absorb the unloading of these securities.  Just to be clear, the interest rates that QE3 are targeting are different from the interest rates you usually hear about. It's possible for the Fed to unwind QE3, while still keeping the ""interest rate"", i.e. the federal funds rate, near zero. although this is considered unlikely. Also, the Fed can target long-term vs. short-term interest rates as well, which is once again slightly different from what I talked about above. This was the goal of the Operation Twist program in 2011 (and in the 1960's). Kirill Fuchs gave a great description of the program in this answer, but basically, the Fed purchased long-term securities and sold short-term securities, with the goal of twisting the yield curve to lower long-term interest rates relative to short-term rates. The goal is to encourage people and businesses to take on long-term debt, e.g. mortgages, capital investments, etc. My main question that I'm trying to understand is why interest rates are what they are. Is it more of an arbitrary number set by central banks or is it due to market activity? Hopefully I addressed much of this above, but I'll give a quick summary. There are many ""interest rates"" in numerous different financial markets. The rate most commonly talked about is the nominal federal funds rate that I mentioned above; although it's a target set by the Board of Governors, it's not arbitrary. There's a reason the Federal Reserve hires hundreds of research economists. No central bank arbitrarily sets the interest rate; it's determined as part of an effort to reach certain economic benchmarks for the foreseeable future, whatever those may be.  In the US, current Fed policy maintains that the federal funds rate should be approximately zero until the economy surpasses the unemployment and inflation benchmarks set forth by the Evans Rule (named after Charles Evans, the president of the Federal Reserve Bank of Chicago, who pushed for the rule). The effective federal funds rate, as well as other rates the Fed has targeted like interest rates on commercial housing debt, long-term rates on Treasury securities, etc. are market driven. The Fed may enter the market, but the same forces of supply and demand are still at work. Although the Fed's actions are controversial, the effects of their actions are still bound by market forces, so the policies and their effects are anything but arbitrary." The Fed controls the base interest rate for lending to banks. It raises this rate when the economy is doing well to limit inflation, and lowers this rate when the economy is doing poorly to encourage lending. Raising the interest rate signals that the Fed believes the economy is strong/strengthening.   Obviously it's more complicated than that but that's the basic idea. "The interest rate offered by a bond is called the nominal interest rate.  The so-called real interest rate is the nominal interest rate minus the rate of inflation. If inflation is equal to or greater than the nominal rate at any given time, the REAL interest rate is zero or negative. We're talking about a ten year bond. It's possible for the real interest rate to be negative for one or two years of the bond's life, and positive for eight or nine.  On the other hand, if we have a period of rising inflation, as in the 1970s, the inflation rate will exceed the (original) interest rate in most years, meaning that the real interest rate on the ten year bond will be negative over its whole life. People lost ""serious"" money on bonds (and loans) in the 1970s. In such situations, the BORROWERS make out. That is, they borrow money at low rates, earn inflation (plus a little more) pay back inflated dollars, and pocket the difference. For them, the money is ""free.""" As no one has mentioned them I will...  The US  Treasury issues at least two forms of bonds that tend to always pay some interest even when prevailing rates are zero or negative.  The two that I know of are TIPS and I series bonds. Below are links to the descriptions of these bonds: http://www.treasurydirect.gov/indiv/research/indepth/tips/res_tips.htm http://www.treasurydirect.gov/indiv/research/indepth/ibonds/res_ibonds.htm "The ""pure play"" would be using interest rate options.  http://www.cboe.com/Products/InterestRateOptionsSpecs.aspx" In the EU, you might be looking for Directive 2000/35/EC (Late Payment Directive). There was a statutory rate, 7% above the European Central Bank main rate. However, this Directive was recently repealed by Directive 2011/7/EU, which sets the statutory rate at ECB + 8%. (Under EU regulations, Directives must be turned into laws by national governments, which often takes several months. So in some EU countries the local laws may still reflect the old Directive. Also, the UK doesn't participate in the Euro, and doesn't follow the ECB rate) "In the United States, if someone refers to the ""interest rate"", especially if heard on news or talk radio in particular, they are almost always referring to the federal funds rate, a rate set forth and maintained by the United States Federal Reserve (the ""fed"" for short). If the fed opts to raise or lower this rate, it subsequently effects all interest rates, whether by being directly connected in a chain of loans  or by market demand through the efficiency of financial markets in the case of bond auctions. The FOMC meets eight times each year to determine the target for the federal funds rate.  The federal funds rate effects all interest rates because it is the originating rate of interest on all loans in the chain of loans. Because of this significance as a benchmark for all interest rates, it is the rate most commonly referred to as ""interest rate"" when used alone. That is why other rates are specified by what they actually are; e.g., mortgage rates; 10 year & 30 year (for 10 year treasury and 30 year treasury bond yields respectively); savings rate, auto rate, credit card rate, CD rate—all rates of interest effected by the originating loan that is the federal funds rate.  This is true in the United States but will vary for other countries. In general though, it will almost always refer to the originating rate for all loans in a given country, institution, etc.  Note that bonds have yields that are based on market demand that is, in turn, based on the federal funds rate. It is because of the efficiency of financial markets that the demand, and thus the yields, are correlated to the federal funds rate." "These rates are so low because the cost of money is so low. Specifically, two rates are near zero.  The Federal Reserve discount rate, which is ""the interest rate charged to commercial banks and other depository institutions on loans they receive from their regional Federal Reserve Bank's lending facility--the discount window."" The effective federal funds rate, which is the rate banks pay when they trade balances with each other through the Federal Reserve. Banks want to profit on the loans they make, like mortgage loans. To do so, they try to maximize the difference between the rates they charge on mortgages and other loans (revenue), and the rates they pay savings account holders, the Federal Reserve or other banks to obtain funds (expenses). This means that the rates they offer to pay are as close to these rates as possible. As the charts shows, both rates have been cut significantly since the start of the recession, either through open market operations (the federal funds rate) or directly (the discount rate). The discount rate is set directly by the regional Federal Reserve banks every 14 days.   In most cases, the federal funds rate is lower than the discount rate, in order to encourage banks to lend money to each other instead of borrowing it from the Fed. In the past, however, there have been rare instances where the federal funds rate has exceeded the discount rate, and it's been cheaper for banks to borrow money directly from the Fed than from each other."