I hope I'm misunderstanding your plan... you want to invest in a way that will make SO MUCH that you pay back all of the loan payments with investment gains? Like the answer I gave on the preceding question, and like @littleadv's comment/mhoran's answers... don't do this. No good will come of it.

This strategy requires higher returns, but does not necessarily give you a better return.

But because you asked the question again, let me specify what you're missing... I do think that learning is a good thing. It boils down to two very significant problems that you haven't addressed:

(1) Where are you getting your monthly "income" from?

(2) Realistic vs. Daydreaming--How big do any gains have to be and does that exist in the real world in a way that you can capture?

In a nutshell, if my answer to the last question showed that it's crazy to invest and pay back out of your capital and income... since you're trying to keep your capital and only pay back with monthly gains, this one will require even higher and thus more unrealistic gains.

The model you're implying:

LOAN DETAILS:          Month 1            Month 2          Month 3
Starting Balance       $10,000            $9,598           $9,194
Payment                432.47             432.47           432.47
Interest Owed          $30                $28.79           $27.582
Principal Paid         402.47             403.67           404.88
Ending Loan Balance    9,598              9,194            8,789
-------
INVESTMENTS:
Capital Invested       $10,000            $10,000          $10,000
"Income" (>Payment)    432.47
Assumed Pre-tax Return 4.323%  <----THAT IS MONTHLY RETURNS = Requires 51.9% Annually
|
(I am ignoring taxes because they simply increase required gains by 25%
... to 64.875% per year)

If that's what you mean with this model, (which I think you do), then here are my two very key questions again:

How are you getting your monthly income? Financial investments (i.e. stocks or bonds) will have two components of value. One component of value is the stream of payments, such as a monthly dividend from stocks that pay those, or the interest payment from a bond. The other is the ability to resell a security to another investor, receiving back your capital.

So... you either have to find Bonds//Dividend stocks that pay >52% returns tax-free each year, and pay this loan off with the payments. (Or higher returns to cover taxes, but these kinds of investments do not exist for you.)

OR you can try to invest in something, pray that it goes up ≥4.323% per month and so that you can sell it, pay back your loan payment with the proceeds, and use the capital to buy your next investment... that will go up 4.323% per month, to turn and sell it again.

The pros that do model this type of speculation go into much more depth than you are capable of. They build models that incorporate probabilities for rates of return based on historical data. They have better information, and have specialized in calculating this all out. They even have access to better investment opportunities (like pre-IPO Twitter or private notes). You just won't find the opportunities to make this happen, each month, for 24 months. (Again, you won't find them. They do not exist for you in as an investor in securities)

Realistic vs. Daydreaming So... clearly I hope that by now I have convinced you that these would be the required returns. They simply aren't available to you. If they were, you would still run into obstacles with converting 'book' returns into physical money that you could repay the loans with, and then continuing that growth.

And while I appreciate the notion that 'if I could just make the payments each month, I'd have $10,000 after 24 months!' I guarantee you that you'll be better off finding another way to target that same investment.

Along the lines of what mhoran said, if you aim for a basic 401K or other similar investment account and target it into the S&P500, you might see returns of anywhere from -25% to +25% over the next 24 months... but if things went like they tend to average for the S&P500, it's more like ~7% annually. Check out a "savings target calculator" like this one from Bankrate.com and put in the numbers... if you can save about $390 a month you'll be at $10K in 24 months. It's not as fun as the other, but you can actually expect to achieve that.

You will not find consistent >50% returns on your money annually.