You are supposing that an American company needs to have been founded in the US. That's not true. There are many tech companies, including 1B+ ones, that were f

You are supposing that an American company needs to have been founded in the US. That's not true. There are many tech companies, including 1B+ ones, that were founded out of the US and then moved there. The availability of capital is so great in the US -even comparing with Europe- that makes a lot of sense to move there.