Tax? Investment or Business?

[Dean D]

1st yr we did my taxes. Flipped 4 homes treated it as an investment and paid capital gains. This 2nd yr the accountant wants to treat the flipping as a business and pay self-emp, taxes.
He wants me to decide, he'll do either way but prefers the later.
I'm sitting on the fence. I feel like its an investement as I am the
$ behind all transactions and sub out 90% of the work. But I also
don't want the IRS coming back later to decide for me.
What are everyones thoughts?
Thanks