If they don't exercise their option to buy within the time period allotted, the option monies and any payments made toward the house are forfeited.
Surprisingly, I have found that only a small percentage of Lease Option buyers will actually exercise the option. (50%-60%) I cover this material in detail in my book.
However, I also understand that in the stock market there are no guarantees! It is for this reason and this reason alone, that diversity is a necessity. If I knew for certain that CMA would continue its program of raising their dividend every year, and that the next 14 years would provide better than 15 percent return on my money, I would only own CMA stock. It is because of this ‘risk of no guarantees' in the stock market that the rewards for investing in the stock market are much higher than a passbook savings account, CD's or Bonds.
The other Wall Street bright idea is the fund of funds (FOF). It sounds good, but it actually creates a double layer of costs; the cost of purchasing the fund itself, and then the expenses of the mutual funds the FOF purchases. Take for example, the Enterprise Group of Funds. It shows an expense ratio of almost 2% plus a sales charge of 4.75% according to Morningstar. Tack on the underlying expenses and you're paying out more than 3% a year in investment expenses.