I would suggest a balanced portfolio of low cost index funds consisting of both domestic bonds and stocks & international stocks.
Your asset allocation into each of these classes should really be based on your age and risk tolerance.
The old rule of thumb is your age in bonds (percentage). Many of the large caps companies already have a big international exposure….so take that into consideration when considering your allocation to international funds.
Fidelity and Vanguard have excellent low cost funds index funds.