How to compute for losses in an upside down trade-in of a financed car?
"Numbers: Estimate you still owe around 37000 (48500 - 4750, 5% interest, 618 per month payment). Initial price, down payment, payments made - none of these mean anything.  Ask your lender, ""What is the payoff of the current loan?"" Next, sell or trade the current vehicle. Compare to the amount owed. Any shortfall has to be repaid, out of pocket, or in some cases added to the price of the new car and included in the principal of the new loan.  You cannot calculate how much you still owe the way you have, because it totally ignores interest. Advice on practicality:  Don't do this.  You will be upside down even worse on the new car from the instant you drive off the lot.  Sell the current vehicle, find a way to pay the difference - one that doesn't involve financing. Cut your losses on the upside down vehicle. Then purchase a new vehicle. I'm in the ""Pay cash for gently used"" school, YMMV. Another option is to go to your bank.  Refinance your car now to get a lower interest rate.  Pay as much of the principal as you can.  Keep that car until it is paid off.  Then you will not be upside down. If you're asking how to use the estimator on the webpage.  Put the payoff in the downpayment as a negative and the trade in value in the trade in spot.  Expect the payment to go up significantly.   Another opinion that might be practical advice.  Nothing we say here will convince your financially responsible spouse that this is a good idea." I think you are making this more complicated that it has to be.  In the end you will end up with a car that you paid X, and is worth Y. Your numbers are a bit hard to follow.  Hopefully I got this right. I am no accountant, this is how I would figure the deal: The payments made are irrelevant.  The downpayment is irrelevant as it is still a reduction in net worth.   Your current car has a asset value of <29,500>.  That should make anyone pause a bit.   In order to get into this new car you will have to finance the shortfall on the current car (29,500), the price of the vehicle (45,300), the immediate depreciation (say 7,000).  In the end you will have a car worth 38K and owe 82K.  So you will have a asset value of <44,000>.  Obviously a much worse situation.  To do this car deal it would cost the person 14,500 of net worth the day the deal was done.  As time marched on, it would be more as the reduction in debt is unlikely to keep up with the depreciation. Additionally the new car purchase screen shows a payment of $609/month if you bought the car with zero down.  Except you don't have zero down, you have -29,500 down.  Making the car payment higher, I estamate 1005/month with 3.5%@84 months.  So rather than having a hit to your cash flow of $567 for 69 more months, you would have a payment of about $1000 for 84 months if you could obtain the interest rate of 3.5%. Those are the two things I would focus on is the reduction in net worth and the cash flow liability.   I understand you are trying to get a feel for things, but there are two things that make this very unrealistic.  The first is financing.  It is unlikely that financing could be obtained with this deal and if it could this would be considered a sub-prime loan.  However, perhaps a relative could finance the deal. Secondly, there is no way even a moderately financially responsible spouse would approve this deal.  That is provided there were not sigificant assets, like a few million. If that is the case why not just write a check? "I'm going to ignore your numbers to avoid spending the time to understand them.  I'm just going to go over the basic moving parts of trading an upside down car against another financed car because I think you're conflating price and value.  I'm also going to ignore taxes, and fees, and depreciation. The car has an acquisition cost (price) then it has a value.  You pay the price to obtain this thing, then in the future it is worth what someone else will pay you. When you finance a car you agree to your $10,000 price, then you call up Mr. Bank and agree to pay 10% per year for 5 years on that $10,000.  Mr. Banker wires over $10,000 and you drive home in your car.   Say in a year you want a different car.  This new car has a price of $20,000, and wouldn't you know it they'll even buy your current car from you.  They'll give you $7,000 to trade in your current car. Your current car has a value of $7,000.  You've made 12 payments of $188.71.  Of those payments about $460 was interest, you now owe about $8,195 to Mr. Banker. The new dealership needs to send payment to Mr. Banker to get the title for your current car.  They'll send the $7,000 they agreed to pay for your car.  Then they'll loan you the additional $1,195 ($8,195 owed on the car minus $7,000 trade in value).   Your loan on the new car will be for $21,195, $20,000 for the new car and $1,195 for the amount you still owed on the old car after the dealership paid you $7,000 for your old car. It doesn't matter what your down-payment was on the old car, it doesn't matter what your payment was before, it doesn't matter what you bought your old car for.  All that matters is how much you owe on it today and how much the buyer (the dealership) is willing to pay you for it. How much of this is ""loss"" is an extremely vague number to derive primarily because your utility of the car has a value.  But it could be argued that the $1,195 added on to your new car loan to pay for the old car is lost."
Assuming you were immersed in math with your CS degree, the book **'A Non-Random Walk Down Wall Street' by Andrew Lo** is a very interesting book about the random walk hypothesis and it's application to financial markets and how efficient markets might not necessarily imply complete randomness.    Lots of higher level concepts in the book but it's an interesting topic if you are trying to branch out into the quant world.  The book isn't very specific towards algorithmic trading but it's good for concept and ideas.  Especially for general finance, that will give you a good run down about markets and the way we tackle modern finance.    **A Random Walk Down Wall Street** (which the book above is named after) by **Burton Malkiel** is also supposed to be a good read and many have suggested reading it before the one I listed above, but there really isn't a need to do so.    For investing specifically, many mention **'The Intelligent Investor' by Benjamin Graham** who is the role model for the infamous Warren Buffet.  It's an older book and really dry and I think kind of out dated but mostly still relevant.  It's more specifically about individual trading rather than markets as a whole or general markets.  It sounds like you want to learn more about markets and finance rather than simply trading or buying stocks.  So I'd stick to the Andrew Lo book first.    ---  Also, since you might not know, it would be a good idea to understand the capital asset pricing model, free cash flow models, and maybe some dividend discount models, the last of which isn't so much relevant but good foundations for your finance knowledge.  They are models using various financial concepts (TVM is almost used in every case) and utilizing them in various ways to model certain concepts.  You'd most likely be immersed in many of these topics by reading a math-oriented Finance book.  Try to stay away from those penny stock trading books, I don't think I need to tell a math major (who is probably much smarter than I am) that you don't need to be engaging in penny stocks, but do your DD and come to a conclusion yourself if you'd like.  I'm not sure what career path you're trying to go down (personal trading, quant firm analyst, regular analyst, etc etc) but it sounds like you have the credentials to be doing quant trading.    ---  Check out www.quantopian.com.  It's a website with a python engine that has all the necessary libraries installed into the website which means you don't have to go through the trouble yourself (and yes, it is fucking trouble--you need a very outdated OS to run one of the libraries).  It has a lot of resources to get into algorithmic trading and you can begin coding immediately.  You'd need to learn a little bit of python to get into this but most of it will be using matplotlib, pandas, or some other library and its own personal syntax. Learning about alpha factors and the Pipeline API is also moderately difficult to get down but entirely possible within a short amount of dedicated time.     Also, if you want to get into algorithmic trading, check out Sentdex on youtube.  He's a python programmer who does a lot of videos on this very topic and has his own tool on quantopian called 'Sentiment Analyzer' (or something like that) which basically quantifies sentiment around any given security using web scrapers to scrape various news and media outlets.  Crazy cool stuff being developed over there and if you're good, you can even be partnered with investors at quantopian and share in profits.    You can also deploy your algorithms through the website onto various trading platforms such as Robinhood and another broker and run your algorithms yourself.    Lots of cool stuff being developed in the finance sector right now.  Modern corporate finance and investment knowledge is built on quite old theorems and insights so expect a lot of things to change in today's world.  ---  With a math degree, finance should be like algebra I back in the day.  You just gotta get familiar with all of the different rules and ideas and concepts.  There isn't that much difficult math until you begin getting into higher level finance and theory, which mostly deals with statistics anyways like covariance and regression and other statistic-related concepts.  Any other math is simple arithmetic. "It's possible the $16,000 was for more than the car.  Perhaps extras were added on at purchase time; or perhaps they were folded into the retail price of the car.  Here's an example.  2014: I'm ready to buy. My 3-year-old trade-in originally cost $15,000, and I financed it for 6 years and still owe $6500.  It has lots of miles and excess wear, so fair blue-book is $4500. I'm ""upside down"" by $2000, meaning I'd have to pay $2000 cash just to walk away from the car.  I'll never have that, because I'm not a saver.  So how can we get you in a new car today?  Dealer says ""If you pay the full $15,000 retail price plus $1000 of worthless dealer add-ons like wax undercoat (instead of the common discounted $14,000 price), I'll eat your $2000 loss on the trade.""  All gets folded into my new car financing.  It's magic! (actually it's called rollover.)  2017: I'm getting itchy to trade up, and doggone it, I'm upside down on this car.  Why does this keep happening to me?  In this case, it's rollover and other add-ons, combined with too-long car loans (6 year), combined with excessive mileage and wear on the vehicle." "I (and probably most considering trading) had a similar thought as you.  I thought if I just skimmed the peaks and sold before the troughs, perhaps aided by computer, I'd be able to make a 2% here, 2% there, and that would add up quickly to a nice amount of money.  It almost did seem ""foolproof"". Then I realized that sometimes a stock just slides...down...and there is no peak higher than what I bought it for.  ""That's OK,"" I'd think, ""I'm sure it will recover and surpass the price I bought it for...so now I play the waiting game.""  But then it continues sliding, and my $10k is now worth $7k.  Do I sell?  Did I build a stop loss point into my computer program?  If so, what is the right place to put that stop?  What if there is a freak dip down and it triggers the stop loss but THEN my stock recovers?  I just lost $14,000 like this last week--luckily, only virtually! The point is, your idea only has half a chance to work when there is a mildly volatile stock that stays around some stable baseline, and even then it is not easy.  And then you factor in fees as others mentioned... People do make money doing this (day traders), and some claim you can use technical analysis to time orders well, so if you want to try that, read about technical analysis on this site or elsewhere." Considering I'm putting 30% down and having my father cosign is there   any chance I would be turned down for a loan on a $100k car? According to BankRate, the average credit score needed to buy a new car is 714, but they also show average interest rates at 6.39% for new-car loans to people with credit scores in the 601-660 range. High income certainly helps offset credit score to some extent.  Not every bank/dealership does things the same way. Being self-employed you'd most likely be required to show 2 years of tax returns, and they'd use those as a basis for your income rather than whatever you have made recently. If using a co-signer, their income matters. Another key factor is debt to income ratio, if too much of someone's income is already spoken for by other debts a lender will shy away. So, yes, there's a chance, given all the information we don't know and the variability with lender policies, that you could be turned down for a car loan. How should I go about this? If you're set on pursuing the car loan, just go talk to some lenders. You'll want to shop around for a good rate anyway, so no need to speculate just go find out. Include the dealership as a potential financing option, they can have great rates. Personally, I'd get a much cheaper car. Your insurance premium on a 100k car will be quite high due to your age. You might be rightly confident in your earning potential, but nothing is guaranteed, situations can change wildly in short order. A new car is not a good investment or a value-retaining asset, so why bother going into debt for one if you don't have to? If you buy something in cash now, you could upgrade in a few years without financing if your earning prediction holds and would save quite a bit in car insurance and interest over the years between. With new cars it's usually the other way around: finance at a low APR or get cash back when you buy it outright. With used cars you usually don't know how much they have invested in the car, so it's more difficult to know how low they're willing to go. Regardless, I do think it's odd that they would knock 2K off the price if you finance with them, but not if you pay cash. The only reason they would do that is if they intend to make at least 2K in interest over the life of the loan, but they have no way of guaranteeing you won't refi. Therefore, I suspect they are bluffing and would probably close the deal if you wrote them a check (or put the cash on the table) for 2K less. However, if they won't budge and will only knock off 2K if you finance, you could finance and pay it off in full a week later. Just make sure they don't have any hidden origination fees or pay-off-early fees. "You say ""it's expensive"".  I'm going to interpret this as ""the monthly payments are too high"". Basically, you need to get your old loan paid off, presumably by selling the car you have now.  This is the tough part.  If you sold the car now, how much would you get for it?  You can use Kelley Blue Book to figure out what the car is roughly worth.  That's not a guarantee that it will actually sell for that much.  Look in your local classifieds to see what similar cars are selling for.  (Keep in mind that you will usually get less for your old car if you trade it in versus sell it yourself.) Now, if you owe more than your car is worth, you're in a really tight spot.  If you don't get enough money when you sell it, you are still stuck with the remainder of the loan.  In that case, it is usually best to just stick with the car you have, and be more cautious about payments and loan length the next time you finance a car. Penalties:  Most car loans don't have any kind of early repayment penalty.  However, you should check your loan paperwork just to make sure." "—they will pull your credit report and perform a ""hard inquiry"" on your file. This means the inquiry will be noted in your credit report and count against you, slightly. This is perfectly normal. Just don't apply too many times too soon or it can begin to add up. They will want proof of your income by asking for recent pay stubs. With this information, your income and your credit profile, they will determine the maximum amount of credit they will lend you and at what interest rate. The better your credit profile, the more money they can lend and the lower the rate.  —that you want financed (the price of the car minus your down payment) that is the amount you can apply for and in that case the only factors they will determine are 1) whether or not you will be approved and 2) at what interest rate you will be approved. While interest rates generally follow the direction of the prime rate as dictated by the federal reserve, there are market fluctuations and variances from one lending institution to the next. Further, different institutions will have different criteria in terms of the amount of credit they deem you worthy of.  —you know the price of the car. Now determine how much you want to put down and take the difference to a bank or credit union. Or, work directly with the dealer. Dealers often give special deals if you finance through them. A common scenario is: 1) A person goes to the car dealer 2) test drives 3) negotiates the purchase price 4) the salesman works the numbers to determine your monthly payment through their own bank. Pay attention during that last process. This is also where they can gain leverage in the deal and make money through the interest rate by offering longer loan terms to maximize their returns on your loan. It's not necessarily a bad thing, it's just how they have to make their money in the deal. It's good to know so you can form your own analysis of the deal and make sure they don't completely bankrupt you.  —is that you can comfortable afford your monthly payment. The car dealers don't really know how much you can afford. They will try to determine to the best they can but only you really know. Don't take more than you can afford. be conservative about it. For example: Think you can only afford $300 a month? Budget it even lower and make yourself only afford $225 a month." "You can greatly reduce the risk if you can line up a buyer prior to purchasing the car.  That kind of thing is common in business, one example is drop shipping.  Also there are sales companies that specialize in these kinds of things bringing manufacturers of goods together with customers.  The sales companies never take delivery of the product, just a commission on the sales.   From this the manufacturers are served as they have gained a customer for their goods.  The buying company is served as they can make a ""better"" end product.  The two parties may have not been brought together had it not been for the sales company so on some level both are happy to pay for the service. Can you find market inequalities and profit from them?  Sure.  I missed a great opportunity recently.  I purchased a name brand shirt from a discount store for $20.  Those shirts typically sell on ebay for $80.  I should have cleaned out that store's inventory, and I bet someone else did as by the time I went back they were gone.   That kind of thing was almost risk-less because if the shirts did not sell, I could simply return them for the full purchase price.  That and I can afford to buy a few hundred dollars worth of shirts. Can you afford to float 45K CDN?  What if it takes a year to sell the car?  What if the economy goes sour and you are left ""holding the bag""?  Why are not car dealers doing exactly what you propose? Here in the US this type of thing is called ""horse trading"" and is very common.  I've both lost and made money on these kind of deals.  I would never put a significant amount of my net worth at risk."