what are the downsides of rolling credit card debt in this fashion
Assuming you can get keep getting credit cards like this forever, you open yourself up to risk in short term losses. Stock/bond prices fluctuate. If you need to pay the money back for some reason (at the end of the 15 months) your investment may be less than the 5,000 you started with. Awesome, you are a math guy.  Very good for you.  In theory, what you are proposing, should work out great as the math works out great.  However have you taken a economics or finance coursework?  The math that they do in these class will leave a most math guys uncomfortable with the imprecision even when one is comfortable with chaos theory. Personal finance is worse.  If it were about math things like reverse mortgages, payday lenders, and advances on one income tax returns would not exist.   The risk derived from the situation you describe is one born out of behavior.  Sometimes it is beyond control of the person attempting your scheme.  Suppose one of these happen: In my opinion the market is risky enough without borrowing money in order to invest.  Its one thing to not pay extra principle to a mortgage in order to put that money in play in the market, it is another thing to do what you are suggesting.  While their may be late fees associated with a mortgage payment, a fixed rate mortgage will not change if you late on payment(s). On these balance transfer CC schemes they will jack your rate up for any excuse possible.  I read an article that the most common way to end up with a 23%+ credit card was to start out with a 0% balance transfer.  One thing that is often overlooked is that the transfer fee paid jacks up the stated rate of the card.   In the end, get out of consumer debt, have an emergency fund, then start investing.  Building a firm financial foundation is the best way to go about it.  Without one it will be difficult to make headway.  With one your net worth will increase faster then you imagined possible.
Sometimes there are credit cards that offer a (promotional) 0% APR on transfers with no transfer fees.  It can be a good option to move the money to one of these if you're disciplined enough to keep hacking away at the debt before the APR jumps. One of the more subtle disadvantages to large credit card purposes purchases (besides what the other answer mentions), is that it makes you less prepared for emergencies. If you carry a large balance on your credit card with the idea that your income can easily handle the payments to beat the no-interest period, you never know when you'll have an unexpected emergency and you'll end up having to pay less, miss the deadline and end up paying huge interest. Even if you are fastidious about saving and budgeting, what if your family comes under a large financial burden (just as one possible example)? The main risk I see to this plan is with a late payment to your credit card.  For a variety of reasons, some outside your control, you could end up with a late payment on the CC and a +18% interest rate making your arbitrage attempts unprofitable. You sense that this is risky, and it derives from placing short-term risk on a long term asset.   Your interest rate is high for the current market.  What kind of things can you do reduce that rate?  What kind of things can you do to reduce your principle?  Those kind of things represent far less risk and accomplish the same goal. I think you'd be adding the transaction fee each time, so let's say it's 3% or minimum $10, your balance would be almost $580 by November.  Unless for some reason you have a permanent no balance transfer fee card or the two cards let you pay bills without charging a cash fee of some sort. The one big drawback I know is when you take the mortgage credit, your credit ability is calculated, and from that sum all of your credits are subtracted, and credit limit on credit card counts as credit...  I don't know if it is worldwide praxis, but at least it is the case in Poland. They don't do anything you can't do yourself and they charge you money for it. And of course the only way they manage to negotiate the debt down is by not paying it for a while in the first place, have it referred to collections and then negotiating with the collectors. At that time, your credit rating (if you care about that at all) will have suffered a lot more damaged than it is from a few late payments. I would address the issue as to why you end up paying late first - it sounds to me like you're cutting the time left to pay to the bone and this turned around and bit you in the you-know-where. In case you are able to pay but not organised enough to do it on time, find a way to remind yourself to pay the bill a few days early for peace of mind. That won't do anything about the 28% interest but those might serve as an additional motivation to pay the debt off faster. Once you're back to showing regular on-time payments on your credit record, you might want to investigate transferring the balance to a cheaper card or negotiate the interest down (or both). If you genuinely can't pay after you've taken care of the essentials (food, shelter, transportation) then you don't need a third party to stop paying the credit card bill, you can do that yourself. "The only way to ""roll"" debt into a home purchase is to have sufficient down payment.  Under the ""new"" lending rules that took effect in Canada earlier this year, you must have at least 5% of the purchase price as a down payment.  If you have $60,000 in additional debt, the total amount of mortgage still cannot be greater than 95% of the purchase price.  Below is an example. Purchase price of home $200,000. Maximum mortgage $190,000 (95% of purchase price) Total outside debt $60,000 That means the mortgage (other than the current debt of $60k) can only be $130,000 This means you would need a down payment of $70,000. Also keep in mind that I have not included any other legal fees, real estate commissions, etc in this example. Since it is safe to assume that you do not have $70k available for a down payment, renting and paying down the debt is likely the better route.  Pay off the credit card(s) first as they have the higher interest amount. Best of luck!" I just want to stress one point, which has been mentioned, but only in passing. The disadvantage of a credit card is that it makes it very easy to take on a credit. paying it off over time, which I know is the point of the card. Then you fell into the trap of the issuer of the card. They benefit if you pay off stuff over time; that's why taking up a credit seems to be so easy with a credit (sic) card. All the technical aspects aside, you are still in debt, and you never ever want to be so if you can avoid it. And, for any voluntary, non-essential, payment, you can avoid it. Buy furniture that you can pay off in full right now. If that means only buying a few pieces or used/junk stuff, then so be it. Save up money until you can buy more/better pieces. This is very much possible and happens quite a lot. In the US, for example, promotional offers by credit card companies where you pay no interest on the balance for a certain period are a very common thing. The lender gains a new customer on such a loan, and usually earns money from the spending via the merchant fees (specifically for credit cards, at least). The pro is obviously free money. The con is that this is usually for a short period of time (longest I've seen was 15 months) after which if you're not careful, high interest rates will be charged. In some cases, interest will be charged retroactively for the whole period if you don't pay off the balance or miss the minimum payment due. "One key point that other answers haven't covered is that many credit cards have a provision where if you pay it off every month, you get a grace period on the interest.  Interest doesn't accrue at all unless you rollover a non-zero balance.  But if you do, you pay interest on the average balance, not the rolled-over balance, for the entire month. You have to ask yourself what you are trying to accomplish with your credit history? Are you trying to maximize your ""buying power"" (really, leverage)?  Or are you trying to make sure that you get the best terms on a moderately sized loan (house mortgage, car note)? As JohnFx and losthorse already noted, it's in the banker's best interest to maximize the profit they make off of you.  Of course, that is not in your best interest. Keeping a credit card balance from month to month definitely feeds the greedy nature of the financing beast.  And makes them willing to take more risks, because the returns are also higher.  But those returns cost you. If you are planning to get sensible loans in the future, that you can comfortably afford, you won't need a maxed credit score.  You won't get the largest loan amounts, but because you are doing the sensible thing and making a large down payment, the risk is also very low and you'll find lenders willing to give you a low interest rate.  Because even though the reward is lower than the compulsive purchaser who pays an order of magnitude more in financing fees, the return/risk ratio is still very favorable to the bank. Don't play the game that maximizes their return.  That happens when you have a loan of maximum size, high interest rate, and struggle to make payments, end up missing a couple and paying late fees, or request forbearance which compounds the interest. Play to minimize risk." If you had a CC issuer that allowed you to do bill-pay this way, I suspect the payment would be considered a cash advance that will trigger a fee and a pretty egregious cash advance specific interest rate.  It's not normal for a credit payment portal to accept a credit card as payment. If you were able to do this as a balance transfer, again there would be fees to transfer the balance and you would not earn any rewards from the transferred balance.  I think it's important to note that cash back benefits are effectively paid by merchant fees.  You make a $100 charge, the merchant pays about $2.50 in transaction fee, you're credited with about $1 of cash back (or points or whatever).  Absent a merchant transaction and the associated fee there's no pot of money from which to apply cash back rewards. Although this scheme is likely to get shut down rather quickly by either your broker or credit card company some points you seem to have missed out on. Properly timed you should be able to get ~55 days of grace period (30 day billing cycle + 25 day grace period) assuming you pay everything off every month and charge immediately following the statement date.  You will need to avoid certain card issuers that code all transactions with financial institutions as cash advances (Citibank in paticular). If it is possible it would be in your best interest to lower cash advance limits to 0 to avoid any chance of cash advance fees. If your credit card attempts to process it as a cash advance the transaction will just be declined and you won't be out anything. Otherwise one cash advance fee will eat several months worth of profits. As far as investments with guaranteed principal goes the only thing you can realistically do is money market accounts and maybe treasury notes. Anything else and the short term price fluctuation may leave you high and dry. If this scheme were to work you would be much better off attempting to get rewards for the purchases than anything you could invest in. If you used a 2% card and churned it every month you would be looking at a 24% return on credit card rewards. Even 1% rewards gives you a 12% annual return which is going to beat anything you could invest the money in. "As Dheer has already told you in his answer, your plan is perfectly legal, and there are no US tax issues other than making sure that you report all the interest that you earn in all your NRE accounts (not just this one) as well as all your NRO accounts, stock and mutual fund dividends and capital gains, rental income, etc to the IRS and pay appropriate taxes. (You do get a credit from the IRS for taxes paid to India on NRO account income etc)  You also may also need to report the existence of accounts if the balance exceeds $10K at any time etc. But, in addition to the foreign exchange conversion risk that Dheer has pointed out to you, have you given any thought to what is going to happen with that credit card? That 0% interest balance of $5K does not mean an interest-free loan 0f $5K for a year (with $150 service charge on that transaction). Instead, consider the following. If you use the card for any purchases, then after the first month, your purchases will be charged interest from the day that you make them till the day they are paid off: there is no 25-day grace period. The only way to avoid this is to pay off the full balance ($5K 0% interest loan PLUS $150 service charge as well as any other service charges, annual fees etc PLUS all purchases PLUS any interest) shown on the first monthly statement that you receive after taking that loan. If you choose this option, then, in effect, have taken a $5K loan for only about 55 days and have paid 3%  interest (sorry, I meant to write) service fee for the privilege. If you don't use the card for any purchases at all, then the first monthly statement will show a statement balance of $5130 and (most likely) a minimum required payment of $200. By law, the minimum required payment is all interest charged for that month($0) PLUS all service fees charged during that month ($150) PLUS 1% of the rest ($50). Well, actually the law says something like ""a sufficient fraction of the balance to ensure that a person making the required minimum payment each month can pay off the debt in a reasonable time"" and most credit card companies choose 1% as the sufficient fraction and 108 months as a reasonable time.  OK, so you pay the $200 and feel that you have paid off the service fee and $50 of that 0% interest loan. Not so!  If you make the required minimum payment, the law allows that amount to be be applied to any part of the balance owing. It is only the excess over the minimum payment that the law says must be applied to the balance being charged the highest rate. So, you have paid off $200 of that $5K loan and still owe the service fee. The following month's statement will include interest on that unpaid $150. In short, to leave only the 0% balance owing, you have to pay $350 that first month so that next month's statement balance will be $4800 at 0%. The next month's required minimum payment will be $48, and so on. In short, you really need to keep on top of things and understand how credit-card payments really work in order to pull off your scheme successfully. Note also that the remaining part of that 0% interest balance must be paid off by the end of the period or else a humongous rate of interest will be applied retroactively from Day One, more than enough to blow away all that FD interest. So make sure that you have the cash handy to pay it off in timely fashion when it comes due." This is pretty simple in theory, harder to do in practice. You will be surprised how quickly the debt will disappear.  Doing these things will work, I know from experience. I do this, and as you say the biggest downside is not having a separate account for your savings.  If you're the type of person who struggles with restraint this is not for you. On the other hand this type of account gives more interest than any other type of US Checking or Savings account I've seen, so you will benefit from the interest.