Does the E-2 visa lead to the green card?

Answer

Not directly — E-2 has no dual intent. But E-2 is an excellent platform to transition to EB-5 (if you've already invested $800K+), EB-1A (if you've developed an extraordinary-ability profile), or EB-2 NIW (if your business has national-interest impact). The E-2 → NIW path is common among entrepreneurs.