Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Tax implications of exercising ISOs and using proceeds to exercise more ISOs
I've never heard of an employer offering this kind of arrangement before, so my  answer assumes there is no special tax treatment that I'm not aware of. Utilizing the clause is probably equivalent to exercising some of your options, selling the shares back to your employer at FMV, and then exercising more options with the proceeds. In this case if you exercise 7500 shares and sell them back at FMV, your proceeds would be 7500 x $5 = $37,500, with which you could exercise the remaining 12,500 options. The tax implications would be (1) short-term capital gains of 7500 x ($5 - $3) = $15,000 and (2) AMT income of 12,500 x ($5 - $3) = $25,000, assuming you don't sell the shares within the calendar year.