You're separated so probably not. In most states, he's obligated to pay you for half the assets earned during the marriage.

You need to look up how valuation dates are calculated in your state.

You asking for this is a bit immoral also. You're separated and he has a right to move on without being indebted to a past relationship except potentially for alimony and/or child support.

For instance, now that you're separated, if you went out, bought a lottery ticket and won...do you think your ex should be entitled to half your winnings? Or if you die a year from now, should he get half of your estate?

That wouldn't be fair, would it?

One thing to consider is start-up business often require much capital without a large return until it is established. There may be nothing for you to get half of but debt. I agree with the previous post that once the separation has been made it is time to move on and let go of the past. Everyone deserves to have that opportunity.

My husband bought into a home with his affair partner after we separated and I was not entitled to any of it.
However, if he had used any undisclosed funds to put a down payment on that new home then I would be entitled to half of that. We were going thru the courts to decide SS and Equalization based on our incomes and assets.