If it can be argued as a settlement then there is zero tax. That would be something you'd need to argue with the IRS about.
Most likely though, your broker or the LT (if checks are issued) will withhold 20% before you even get your hands on it.
If your income is less than $450k then you would be entitled to a refund of 5% on that amount up to 450k.
Also, there is still a 3.8% tax taken for Obamacare too, unless they get it repealed before disbursement. That could be why the hedgies are allowing this to drag on. 3.8% is big money when you are talking billions.
All IMO based on talks with three CPAs about this. Good news is, it is NOT taxed as ordinary income!